# Pre Algebra Percent of Change

Section 7: Applications of Percent: Lecture 4 | 11:27 min

In this lesson our instructor talks about percent of change. She talks about finding a percent of increase, converting units, and finding a percent of decrease. Four extra example videos round up this lesson.

Nancy Fung

Percent of Change

Slide Duration:Table of Contents

13m 41s

- Intro0:00
- What You'll Learn and Why0:08
- Topics Overview0:09
- Vocabulary0:22
- Order of Operations0:26
- Numerical Expression1:03
- Simplify1:27
- Simplifying an Expression1:44
- Example 1: Simplify the Expression1:45
- Simplifying an Expression3:26
- Example 2: Simplify the Expression3:27
- Using an Expression to Solve a Problem4:29
- Example 3: Babysitting4:33
- Using an Expression to Solve a Problem6:14
- Example 4: Shopping6:17
- Extra Example 1: Simplify the Expression7:35
- Extra Example 2: Simplify the Expression8:55
- Extra Example 3: Finding Total Cost10:02
- Extra Example 4: Finding Total Cost11:44

9m 11s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:16
- Variable0:19
- Algebraic Expression0:30
- Evaluate0:51
- Modeling an Algebraic Expression1:16
- Model the Expression 2x + 41:17
- Evaluating an Algebraic Expression1:47
- Evaluate 3x - 7 for x = 8.21:48
- Evaluating an Algebraic Expression2:45
- Evaluate (3.7 + x) ÷ 2 for x = 9.62:46
- Using a Table to Evaluate an Expression4:10
- Example: Pairs of Shoes4:13
- Extra Example 1: Evaluate the Expression5:46
- Extra Example 2: Evaluate the Expression6:06
- Extra Example 3: Perimeter of a Rectangle6:46
- Extra Example 4: Finding Income7:40

8m 24s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:15
- Addition0:26
- Subtraction1:04
- Multiplication2:06
- Division2:31
- Translating Words to Expressions3:02
- Example: 9 Less than Twice a Number3:08
- Writing an Algebraic Expression3:58
- Example: Cost of Bowling4:07
- Extra Example 1: Writing Expressions5:14
- Extra Example 2: Writing Expressions6:06
- Extra Example 3: Writing Expressions7:11
- Extra Example 4: Writing Expressions7:58

10m 20s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:16
- Compatible Numbers0:17
- Estimating by Rounding1:08
- Estimate 36 + 6 + 581:30
- Estimate 94 - 35 - 422:29
- Estimating with Compatible Numbers3:02
- Estimate 297 ÷ 173:17
- Estimate 9 Times 383:39
- Estimating for Reasonableness4:13
- Example: Total Cost of the Items4:15
- Extra Example 1: Estimating with Compatible Numbers6:02
- Extra Example 2: Estimating by Rounding7:05
- Extra Example 3: Estimating for Reasonableness7:27
- Extra Example 4: Estimating for Reasonableness9:15

12m 1s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:16
- Commutative Properties: Addition and Multiplication0:21
- Associative Properties: Addition and Multiplication1:46
- Vocabulary Cont.3:08
- Identity Properties: Addition and Multiplication3:09
- Recognizing Properties3:55
- Examples: Which Property is Illustrated?3:58
- Using Properties of Numbers5:07
- Using Mental Math to Find the Total Cost5:18
- Using Properties of Numbers6:29
- Using Mental Math to Simplify6:30
- Extra Example 1: Using Properties of Numbers8:29
- Extra Example 2: Using Properties of Numbers9:06
- Extra Example 3: Using Properties of Numbers10:02
- Extra Example 4: Using Properties of Numbers10:32

9m 40s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:15
- Distributive Property0:16
- Using the Distributive Property1:32
- Example: 8 ( 9 + 11 )1:35
- Using the Distributive Property2:58
- Example: 7 ( 12 - h )2:59
- Example: ( m + 2 ) 53:20
- Distributive Property in Mental Math3:34
- Example: Finding Total Cost3:38
- Extra Example 1: Summer Job4:55
- Extra Example 2: Total Cost6:03
- Extra Example 3: Fundraiser7:36
- Extra Example 4: Tomato Plants8:24

11m 35s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:10
- Vocabulary0:21
- Opposites0:27
- Integers1:03
- Absolute Value1:23
- Vocabulary2:21
- Number Line2:23
- Finding Absolute Value2:35
- Example: Absolute Value2:36
- More Examples4:05
- Example: Absolute Value of 54:06
- Example: Absolute Value of Negative 24:15
- Comparing Integers4:29
- Boiling Points of Elements4:34
- Comparing Integer Examples6:00
- Example 1: Comparing Integers6:04
- Example 2: Comparing Integers6:17
- Example 3: Comparing Integers6:30
- Comparing Integer Examples6:49
- Comparing Temperature6:53
- Extra Example 1: Simplify Absolute Value8:13
- Extra Example 2: Simplify Absolute Value9:01
- Extra Example 3: Simplify Absolute Value9:29
- Extra Example 4: Simplify Absolute Value10:49

10m 20s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:26
- Integers0:30
- Adding Positive Integers0:55
- Example : -3 + -71:01
- Example : +11 + 81:06
- Example : 2 + (+6)1:21
- Adding Negative Integers1:43
- Example: -3 + -71:48
- Example: -21 + -32:05
- Example: -11 + (-4)2:41
- Adding Integers with Opposite Signs3:01
- Using a Number Line: -8 + 103:52
- Using a Number Line: 4 + (-6)4:36
- Adding Integers with Opposite Signs5:39
- Using Absolute Value: -18 + 75:48
- Extra Example 1: Adding Integers6:33
- Extra Example 2: Adding Integers7:23
- Extra Example 3: Money Problem8:46
- Extra Example 4: Measurement Problem9:15

12m 1s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:21
- Integers0:25
- Opposites0:47
- Rules for Multiplying Signs1:18
- Using a Number Line2:00
- Example: 2 - 52:25
- Other Examples2:52
- Using Number Line: 10 - (-13)3:02
- Rewriting Absolute Value4:51
- Extra Example 1: Subtracting Integers5:48
- Extra Example 2: Temperature7:26
- Extra Example 3: Depth8:51
- Extra Example 4: Change in Yards11:09

14m 28s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:43
- Integers0:47
- Opposites1:03
- Repeated Addition1:41
- Example 1: Using a Number Line1:43
- More Examples3:28
- Example 2: Using a Number Line3:30
- Using a Number Line4:45
- Example 3: Using a Number Line4:46
- Example 4: Using a Number Line5:59
- Rules for Multiplying Same Sign Integers7:20
- Arithmetic7:35
- Algebra8:00
- Rules for Multiplying Different Signs Integers8:17
- Arithmetic8:29
- Algebra8:58
- Multiplying Integer Examples9:20
- Examples of Multiplying Integers9:21
- Using Multiplication of Integers to Solve a Problem10:07
- Elevation10:12
- Temperature11:21
- Determine the Sign of the Product12:19
- Example 5: Determine the Sign12:20
- Example 6: Determine the Sign12:50
- Extra Example 1: Product of Three Negative Numbers13:07
- Extra Example 2: Product of Four Negative Numbers13:45
- Extra Example 3: Product of Five Negative Numbers13:58
- Extra Example 4: Product of 103 Negative Numbers14:13

20m 18s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:27
- Quotient0:30
- Rules for Dividing Integers0:49
- Arithmetic (Same Sign Integers)1:03
- Algebraic (Same Sign Integers)1:36
- Rules for Dividing Integers, cont.2:06
- Arithmetic (Different Signs Integers)2:14
- Algebraic (Different Signs Integers)2:41
- Dividing Integer Examples3:24
- Dividing Integers: 14 ÷ 73:30
- Dividing Integers: 45 ÷ (-9)3:37
- Dividing Integer Examples3:51
- Dividing Integers: (-105) ÷ (-15)3:55
- Dividing Integers: (-42) ÷ 65:07
- Average Rate of Change5:17
- Using Integers to Represent the Situation5:25
- Example: Spend $360 in 6 Days5:40
- Example: Runs 1000 Feet in 4 Minutes6:30
- Average Rate of Change Word Problems7:27
- Example: Average Decrease in Value7:32
- Average Rate of Change Word Problems9:19
- Example: Average Increase in Stock9:23
- Average Rate of Change Word Problems10:46
- Example: Average Increase in Speed10:51
- Dividing Integers12:00
- Odd Number of Negatives12:03
- Even Number of Negatives12:49
- Order of Operations and Sign of Final Answer13:50
- Example: -120 ÷ (-5) ÷ -413:56
- Extra Example 1: Order of Operations14:48
- Extra Example 2: Evaluate the Expression15:29
- Extra Example 3: Rate of Change17:18
- Extra Example 4: Rate of Evaporation19:22

20m 5s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:26
- Factor0:32
- Exponent1:16
- Vocabulary1:57
- Base1:58
- Power2:18
- Writing Expressions with Exponents2:31
- Example 1: Writing Expressions with Exponents2:36
- Example 2: Writing Expressions with Exponents3:00
- Writing Expressions with Exponents3:20
- Example 3: Writing Expressions with Exponents3:25
- Example 4: Writing Expressions with Exponents3:53
- Simplifying Power4:06
- Example 5: Simplifying Power4:14
- Example 6: Simplifying Power5:03
- Simplifying Power6:06
- Example 7: Simplifying Power6:09
- Example 8: Simplifying Power6:50
- Order of Operations7:24
- PEMDAS7:26
- Order of Operations8:32
- Multiplying/Dividing and Adding/Subtracting8:34
- Evaluating Expressions with Exponents10:07
- Example 9: Evaluating Expressions with Exponents10:11
- Example 10: Evaluating Expressions with Exponents11:07
- Extra Example 1: Evaluate12:33
- Extra Example 2: Evaluate13:42
- Extra Example 3: Height of the Rocket15:00
- Extra Example 4: Number of Cells16:38

21m 47s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:18
- Equation0:21
- Isolate1:00
- Inverse Operations1:18
- Subtraction Property of Equality1:59
- Arithmetic2:12
- Algebraic2:53
- Inverse Operations3:32
- Example: 38 + x = 423:40
- Using Substitution to Check Answer4:43
- Inverse Operations5:19
- Example: y + 7.3 = 9.15:22
- Using Substitution to Check Answer5:53
- Draw a Model6:26
- Weight Gain6:42
- Draw a Model8:20
- Mountain Climber8:23
- Examples by Writing Equations10:25
- Calculating Profit: Sweat Shirt10:30
- Examples by Writing Equations11:37
- Calculating Profit: Car Dealer11:38
- Extra Example 1: Inverse Operation14:21
- Extra Example 2: Inverse Operation15:37
- Extra Example 3: Real Estate17:23
- Extra Example 4: Birth Date20:06

19m 34s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:07
- Vocabulary0:23
- Addition Property of Equality: Arithmetic0:31
- Addition Property of Equality: Algebraic1:14
- Subtraction Property of Equality: Arithmetic1:54
- Subtraction Property of Equality: Algebraic2:19
- Solving an Equation by Adding3:05
- Example: b - 2 = 23:22
- Example: 23 - j = 124:00
- Solving an Equation by Adding5:29
- Example: a - 7.9 = 17.95:32
- Example: -5.6 + x = 10.26:33
- Solving an Equation by Writing an Equation7:42
- Example: Bank Withdrawal7:48
- Solving an Equation by Writing an Equation9:21
- Example: Temperature9:23
- Extra Example 1: Solving Subtraction Equations11:50
- Extra Example 2: Solving Subtraction Equations12:46
- Extra Example 3: Money13:40
- Extra Example 4: Selling Price16:01

26m 11s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:19
- Division Property of Equality: Arithmetic0:27
- Division Property of Equality: Algebraic1:05
- Multiplication Property of Equality: Arithmetic1:38
- Multiplication Property of Equality: Algebraic2:07
- Vocabulary2:49
- Inverse Operations2:53
- Solve the Equation Using Division3:09
- Example: 8x = 563:12
- Example: -6y = 423:59
- Solve the Equation Using Division4:47
- Example: 0.9c = 1.894:53
- Solve the Equation Using Division6:11
- Example: Saving Money6:17
- Example: Soccer Team8:14
- Solve the Equation Using Multiplication9:56
- Example: a/7 = 910:04
- Example: t/1.7 = 610:52
- Solve the Equation Using Multiplication12:09
- Example: y/-45 = 3.212:17
- Example: -p = 1413:13
- Solve the Equation Using Multiplication14:10
- Example: Distant14:16
- Extra Example 1: Solve the Equation15:58
- Extra Example 2: Solve the Equation17:25
- Extra Example 3: Height of an Elephant20:55
- Extra Example 4: Money23:07

19m 10s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Two-Step Equation Involvement0:19
- Solving Two-Step Equations0:41
- Example: 8y - 11 = 320:45
- Example: 32 = t/5 + 82:55
- Solving Two-Step Equations4:49
- Example: Recommended Daily Intake4:59
- Solving Two-Step Equations7:01
- Example: Cost of Each Ride7:02
- Extra Example 1: Solving Two-Step Equations10:13
- Extra Example 2: Solving Two-Step Equations12:54
- Extra Example 3: Length of Phone Call13:56
- Extra Example 4: Cost of Owning a Pet16:40

12m 16s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:16
- Perfect Square0:20
- Square Root0:46
- Square Roots1:13
- Every Positive Number has Two Square Roots1:14
- Square Roots of a Number are Opposites1:40
- Square Root Symbol1:54
- Positive Square Root of a Number1:56
- Compare: √25 and -√252:08
- Find the Square Root2:50
- Example: Square Root of 812:52
- Example: Square Root of 1213:13
- Estimating Square Roots3:29
- Example: Square Root of 233:35
- Example: Square Root of 3904:13
- Example: Negative Square Root of 1254:50
- Estimating Square Roots5:27
- Estimating Length5:31
- Simplifying Square Roots7:05
- Example: Square Root of 367:08
- Example: Simplifying Square Roots7:47
- Extra Example 1: Estimate the Length8:21
- Extra Example 2: Simplify the Expression9:05
- Extra Example 3: Estimate the Length9:50
- Extra Example 4: Simplify the Expression10:34

14m 49s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:36
- Right Triangle0:39
- Legs0:57
- Hypotenuse1:02
- Pythagorean Theorem1:11
- Arithmetic Example1:12
- Algebra Example2:41
- Find the Length of the Hypotenuse3:04
- Example 1: Hypotenuse of a Triangle3:07
- Example 2: Hypotenuse of a Triangle4:30
- Find the Length of the Hypotenuse6:18
- Example 3: Hypotenuse of a Right Triangle6:19
- Extra Example 1: Square Roots8:41
- Extra Example 2: Perimeter9:43
- Extra Example 3: Length of Screen11:58
- Extra Example 4: Length of Wire13:14

16m 15s

- Intro0:00
- What You'll Learn and Why0:07
- Topics Overview0:08
- Vocabulary0:30
- The Pythagorean Theorem0:32
- Find the Length of a Leg1:14
- Example 1: Length of Ramp1:19
- Example: 2 Length of Platform4:22
- Identifying a Right Triangle6:13
- Example 3: Determine Right Triangle6:14
- Example 4: Determine Right Triangle8:08
- Extra Example 1: Find the Missing Leg Length10:04
- Extra Example 2: Length of Ladder11:39
- Extra Example 3: Determine Given Lengths13:04
- Extra Example 4: Length of Pole14:20

16m 40s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:23
- Factor0:24
- Composite Number1:04
- Vocabulary1:17
- Prime Number1:18
- Prime Factorization1:57
- Divisibility Rules2:54
- Divisibility Rules for 2, 3, 4 ,5 ,6, 9 and 102:55
- Finding Factors4:56
- Possible Arrangements4:59
- Finding Factors6:06
- How Many Oranges?6:07
- Prime or Composite6:43
- Prime or Composite: 486:47
- Prime or Composite: 537:09
- Prime or Composite: 577:35
- Prime Factorization8:16
- Prime Factorization of 428:23
- Prime Factorization of 848:47
- Find the Number9:23
- Find the Number with the Given Prime Factorization9:24
- Extra Example 1: Prime or Composite11:04
- Extra Example 2: Prime Factorization of 7212:23
- Extra Example 3: Marching Arrangements12:56
- Extra Example 4: Flowers Arrangements14:50

14m 16s

- Intro0:00
- What You'll Learn and Why0:07
- Topics Overview0:08
- Vocabulary0:41
- Factor0:43
- Common Divisor1:00
- Greatest Common Divisor (GCD)/ Greatest Common Factor (GCF)1:16
- Find the GCD by Listing Divisors1:34
- GCD of 27 and 361:46
- GCD of 18 and 492:52
- Prime Factorization to Find GCD3:30
- GCD of 42 and 723:42
- GCD of 21 and 634:46
- GCD in Word Problems5:30
- Greatest Number of Police Officers5:32
- GCD in Word Problems7:15
- Cutting Two Pipes7:16
- Extra Example 1: GCD of 32, -24, 408:08
- Extra Example 2: How Many Groups?9:41
- Extra Example 3: GCD of Two Prime Numbers11:34
- Extra Example 4: How Many Children?12:26

11m 22s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:21
- Equivalent Fractions0:23
- Simplest Form1:15
- Creating Equivalent Fractions1:59
- Method to Create Equivalent Fractions2:00
- Equivalent Fractions2:18
- Write Two Fractions Equivalent to 5/82:22
- Write Two Fractions Equivalent to 2/143:12
- GCD to Simplify3:51
- Find the GCD of 24 and 324:03
- Write 24/32 in Simplest Form4:43
- Write -27/45 in Simplest Form5:08
- Writing a Fraction6:04
- Example: What Fraction of the Vehicles are Trucks?6:11
- Writing a Fraction7:45
- Example: What Fraction of the Seats are Empty?7:55
- Extra Example 1: Pizza9:00
- Extra Example 2: Driving Time9:28
- Extra Example 3: Simplest Form10:29
- Extra Example 4: Basketball Team10:52

20m 47s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:08
- Vocabulary0:30
- Rational Number0:31
- Terminating Decimal0:53
- Repeating Decimal1:04
- Converting Decimals to Fractions1:22
- Write 0.47 as a Fraction1:26
- Write 0.48 as a Fraction2:03
- Write 0.245 as a Fraction3:21
- Converting Decimals to Fractions4:20
- Write 0.08 as a Fraction4:30
- Write 0.8 as a Fraction4:53
- Converting Fractions to Decimals5:26
- Write 1/2 as a Decimal5:30
- Write 6/33 as a Decimal6:12
- Write -9/5 as a Decimal7:39
- Converting Fractions to Decimals in Word Problems8:19
- Batting Average8:23
- Converting Fractions to Decimals in Word Problems11:22
- Cooking Festival11:26
- Extra Example 1: Write 0.038 as a Fraction14:45
- Extra Example 2: Write -13/7 as a Decimal15:35
- Extra Example 3: Batting Average16:38
- Extra Example 4: Rational Number19:55

20m 21s

- Intro0:00
- What You'll Learn and Why0:07
- Topics Overview0:08
- Vocabulary0:29
- Least Common Multiple (LCM)0:30
- Least Common Denominator (LCD)1:50
- Ordering Rational Numbers2:45
- Numbers as Decimals2:46
- Numbers as Fractions5:36
- Compare Each Pair of Numbers8:10
- Compare 3/4 and 4/58:11
- Compare 3/11 and 1/68:44
- Comparing rational Numbers in Word Problems9:19
- Cookies or French Fries?9:22
- Extra Example 1: Least to Greatest (Decimals)11:32
- Extra Example 2: Least to Greatest (Fractions)13:35
- Extra Example 3: Music Notes15:54
- Extra Example 4: Chocolate or Fruit17:16

15m 4s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:19
- Least Common Multiple (LCM)0:20
- Least Common Denominator (LCD)0:28
- Adding Fractions with Unlike Denominators1:22
- Example: 3/4 + 2/51:28
- Example: -3/5 + 1/72:29
- Adding Different Forms of Rational Numbers3:23
- Example: Change to Fractions3:31
- Example: Change to Decimals5:14
- Extra Example 1: Adding Different Forms of Numbers7:02
- Extra Example 2: Exercising10:06
- Extra Example 3: Adding Different Forms of Numbers11:20
- Extra Example 4: Cooking Recipe13:47

14m 40s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:19
- Least Common Denominator (LCD)0:20
- Subtracting with Unlike Denominators0:41
- Example: 5/9 - 3/50:44
- Example: 3/4 - 7/81:23
- Subtracting Rational Numbers1:59
- Example: 23/4 - 3.52:05
- Example: 11.7 - 3/43:39
- Subtracting Rational Numbers in Word Problems4:37
- Puppy's Weight4:41
- Extra Example 1: Subtracting with Unlike Denominators6:48
- Extra Example 2: Subtracting Rational Numbers7:27
- Extra Example 3: Rainfall10:32
- Extra Example 4: Decorating Your House12:06

11m 2s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:17
- Rational Number0:18
- Exponent0:30
- Power0:35
- Multiplying Decimals0:47
- Example 1: Multiplying Decimals0:50
- Example 2: Multiplying Decimals1:18
- Multiplying Rational Numbers in Word Problems1:51
- Example: Length of Pipes1:56
- Raising a Fraction to a Power2:58
- Examples: Raising Fractions to Power2:59
- Extra Example 1: Multiplying Fractions4:45
- Extra Example 2: Compare Fractions5:34
- Extra Example 3: Flour7:28
- Extra Example 4: Income8:50

12m 8s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:22
- Reciprocal0:26
- Finding the Reciprocal0:56
- Example: Reciprocal of 2/31:00
- Example: Reciprocal of 81:04
- Example: Reciprocal of -1/21:10
- Dividing Rational Numbers1:28
- Example 1: Dividing Rational Numbers1:35
- Example 2: Dividing Rational Numbers2:09
- Example 3: Dividing Rational Numbers2:35
- Dividing Rational Numbers in Word Problems3:56
- Example: Chocolate Peanuts4:00
- Extra Example 1: Dividing Decimals5:17
- Extra Example 2: Dividing Fractions7:09
- Extra Example 3: Search Committee8:34
- Extra Example 4: Stake10:18

13m 43s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- What You'll Learn and Why0:23
- Isolate0:24
- Solving Equations with Fractions0:41
- Example: n + 1/2 = 11/120:44
- Example: 3/5 - a = 13/201:34
- Writing Equations with Fractions3:08
- Example: Thickness3:11
- Extra Example 1: Solving Equations6:01
- Extra Example 2: Solving Equations6:58
- Extra Example 3: School Lunches8:23
- Extra Example 4: Fashion Designer10:44

11m 10s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:20
- Multiplicative Inverse0:21
- Solve Each Equation0:51
- Example 1: Solve the Equation0:57
- Example 2: Solve the Equation2:39
- Writing Multiplication Equations3:30
- Example: Water Level3:34
- Extra Example 1: Solve the Equation5:15
- Extra Example 2: Solve the Equation6:28
- Extra Example 3:Money7:26
- Extra Example 4: Solve the Equation9:45

6m 41s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:22
- Zero Exponents: Arithmetic Definition0:27
- Zero Exponents: Algebra Definition0:39
- Negative Exponents: Arithmetic Definition0:46
- Negative Exponents: Algebra Definition1:03
- Simplifying Exponents1:18
- Examples: Simplifying Exponents1:21
- Fractions and Negative Exponents2:41
- Examples: Fractions and Negative Exponents2:45
- Extra Example 1: Negative Exponent3:58
- Extra Example 2: Zero Exponent4:30
- Extra Example 3: Fraction and Negative Exponent4:40
- Extra Example 4: Subtracting Numbers with Exponents5:00

7m 5s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:22
- Ratio0:23
- Equivalent Ratios0:40
- Writing a Ratio1:18
- Write the Ratio in Three Ways1:21
- Writing an Equivalent Ratio2:07
- Different Ratios Equivalent to 10:122:08
- Writing a Ratio in Simplest Form2:47
- Write the Ratio in Simplest Form2:50
- Extra Example 1: Write the Ratio3:32
- Extra Example 2: Ratio in Simplest Form4:38
- Extra Example 3: Write the Ratio5:08
- Extra Example 4: Ratio in Simplest Form5:48

12m 45s

- Intro0:00
- What You'll Learn and Why0:04
- Topics Overview0:05
- Vocabulary0:18
- Rate0:22
- Unit Rate0:40
- Finding a Unit Rate1:00
- Example: Delivery Rate1:03
- Using a Unit Rate1:46
- Example: Miles and Gallon of Gas1:49
- Comparing Unit Rates2:52
- Example: Which is the Better Buy2:58
- Extra Example 1: Calories6:30
- Extra Example 2: Typing Speed7:22
- Extra Example 3: Which is the Better Buy8:23
- Extra Example 4: Wages10:48

16m 19s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:15
- Conversion Factor0:16
- Dimensional Analysis0:23
- Conversion Chart: Length0:32
- Conversion Chart: in, ft, yd, and m0:33
- Conversion Chart: Weight0:49
- Conversion Chart: oz, lb, and t0:50
- Conversion Chart: Capacity0:59
- Conversion Chart: fl oz, cup, pt, qt, and gal1:00
- Converting Units1:17
- Example: Convert 1.3 Miles Into Feet1:18
- Converting Units3:14
- Example: Convert Pounds to Ounces3:15
- Example: Convert Cups to Fluid Ounces3:52
- Converting Units in a Rate4:30
- Unit Rate: 2,200 m in 17.2 min4:31
- Using Dimensional Analysis8:06
- Example: Planning Project8:07
- Extra Example 1: Converting Units9:15
- Extra Example 2: Unit Rate10:31
- Extra Example 3: Planning Project12:15
- Extra Example 4: Converting Units13:45

17m 42s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:18
- Rate0:22
- Unit Rate0:27
- Finding Total Distance0:32
- Example: Total Distance0:33
- Finding Average Speed2:49
- Example: Car's Average Speed2:53
- Using a Unit Rate6:31
- Example: Weight and Spring6:32
- Extra Example 1: Total Distance8:08
- Extra Example 2: Bird's Average Speed10:33
- Extra Example 3: Cost of Shirts13:37
- Extra Example 4: Cost of Bottles15:22

14m 36s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:16
- Proportion0:17
- Cross Products0:45
- Identifying a Proportion11:28
- Example: Do the Ratios Form a Proportion?11:29
- Solving Proportions Using Two Methods2:47
- Example: x/4 = 12/213:03
- Example: 20/y = 15/94:43
- Solving Proportions in Word Problems5:56
- Example: Find the Unit Rate of Exchange6:00
- Extra Example 1: Does the Ratio Form a Proportion?9:55
- Extra Example 2: Solving Proportions10:53
- Extra Example 3: Find the Length of the Photo11:33
- Extra Example 4: Distance12:59

10m 13s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:24
- Percent0:25
- Compare a Fraction to a Decimal to a Percent0:35
- Example: 31 out of 1000:39
- Write a Percent as a Fraction1:11
- Example: Write 47% as a Fraction1:12
- Example: Write 25% as a Fraction1:59
- Write a Fraction as a Percent2:38
- Example: Write 2/10 as a Percent2:39
- Example: Write 57/100 as a Percent3:22
- Example: Write 3/25 as a Percent3:57
- Write a Decimal as a Percent4:48
- Example: Write 0.85 as a Percent4:49
- Example: Write 0.3 as a Percent5:05
- Example: Write 0.04 as a Percent5:17
- Extra Example 1: Write Percent as Decimal and Fraction5:34
- Extra Example 2: Write Fraction as Decimal and Percent6:47
- Extra Example 3: Write Percent as Fraction and Decimal7:41
- Extra Example 4: Fraction, Percent, and Decimal of Students8:36

8m 39s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:20
- Percent0:21
- Finding a Percent0:26
- Example: Find 15% of 1000:27
- Example: Find 10% of 1351:08
- Finding More Percents2:23
- Example: Find 8% of 652:25
- Example: Find 120% of 502:45
- Estimating a Percent3:25
- Example: Estimate 10% of 31.053:38
- Example: Estimate 15% of 31.053:54
- Example: Estimate 20% of 31.054:55
- Extra Example 1: Find 7% of 1205:35
- Extra Example 2: Find 125% of 756:01
- Extra Example 3: Estimate 15% Tip7:02
- Extra Example 4: Estimate 20% Tip8:01

15m 38s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:23
- Proportion0:33
- Cross Products0:38
- Finding Part of a Whole1:07
- Method 1: Find 50% of 361:11
- Method 2: Find 50% of 362:23
- Finding Part of a Whole, cont.3:06
- Example: Find 65% of 1433:07
- Finding the Whole Amount3:44
- Example: How Many Students are in 8th Grade?3:45
- Finding the Whole Amount, cont.5:18
- Example: How Many Students are in the School?5:19
- Finding a Percent6:38
- Method 1: What Percent of 175 is 1057:21
- Method 2: What Percent of 175 is 1058:49
- Finding a Percent, cont.9:57
- What Percent of 115 is 46?9:58
- Extra Example 1: Find 8% of 4811:09
- Extra Example 2: 9 is 25% of What Number?11:34
- Extra Example 3: How Many Students are in the Class?12:39
- Extra Example 4: 66 is What Percent of 55?14:25

11m 27s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:17
- Percent of Change0:18
- Amount of Change/ Original Amount0:26
- Finding a Percent of Increase1:04
- Example: Find the Percent of Increase1:06
- Converting Units2:56
- Example: Converting Units and Percent Increase3:00
- Finding a Percent of Decrease5:08
- Example: Find the Percent of Decrease5:09
- Extra Example 1: Find the Percent of Increase6:32
- Extra Example 2: Find the Percent of Decrease7:30
- Extra Example 3: Find the Percent of Increase8:28
- Extra Example 4: Find the Percent of Decrease10:23

12m 55s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:22
- Markup0:23
- Selling Price0:28
- Formula of Markup0:32
- Formula for Discount1:06
- Finding a Percent of Markup1:16
- Example: Find the Percent of Markup1:19
- Finding a Percent of Discount3:19
- Example: Find the Percent of Discount3:21
- Finding a Sale Price5:03
- Example: Find the Sale Price of the Stereo System5:10
- Extra Example 1: Find the Percent of Markup6:39
- Extra Example 2: Find the Percent of Discount8:57
- Extra Example 3: Find the Percent of Discount9:52
- Extra Example 4: Find the Percent of Discount10:44

15m 13s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:17
- Coordinate Plane0:23
- y-axis0:29
- x-axis0:33
- Quadrants0:37
- More Vocabulary0:49
- Origin0:50
- Ordered Pair0:53
- x-coordinate1:00
- y-coordinate1:08
- Labeling Vocabulary1:24
- Example: Label the Vocabulary1:25
- Graphing Points on a Coordinate Plane3:08
- Example: Graph and Label the Locations3:12
- Quadrants6:18
- Example: Name the Quadrants of Each Ordered Pair6:23
- Extra Example 1: Draw and Label10:18
- Extra Example 2: Graph the Ordered Pair11:20
- Extra Example 3: Graph the Ordered Pair12:42
- Extra Example 4: Name the Quadrants of Each Ordered Pair13:32

18m 36s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:18
- x-coordinate0:21
- y-coordinate0:28
- Pythagorean Theorem0:34
- Finding Lengths of Line Segments1:02
- Example: Find the Length of the Horizontal Line Segment1:05
- Finding Lengths of Line Segments3:50
- Example: Find the Length of the Vertical Line Segment3:54
- Finding Distance in the Coordinate Plane5:59
- Example: Find the Length of the Hypotenuse6:02
- Extra Example 1: Find the Distance Between Two Points7:36
- Extra Example 2: Find the Length of the Line Segment10:13
- Extra Example 3: Find the Length of the Line Segment14:28
- Extra Example 4: How Far is Your School from the Arcade?16:02

14m 29s

- Intro0:00
- What You'll Learn and Why0:04
- Topics Overview0:05
- Vocabulary0:24
- Function0:25
- Function Rule0:51
- Evaluating a Function Rule0:59
- Example: Table of Input and Output1:00
- Using Function Notation2:56
- Example: Write the Equation and Evaluate the Cost2:59
- Writing Functions4:40
- Example: Writing Function4:41
- Extra Example 1: Complete the Table6:02
- Extra Example 2: Complete the Table and Find the Function7:38
- Extra Example 3: Function Notation9:39
- Extra Example 4: Write a Function and Find the Total Cost11:49

16m 2s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:21
- Solution0:22
- Linear Equation0:29
- Linear Function0:44
- Making a Graph from a Table1:05
- Example: Total Savings in Dollars1:08
- Graphing a Linear Function3:03
- Example: Graph the Linear Function3:07
- Extra Example 1: How Much Cereal is Left?5:42
- Extra Example 2: Graph the Value7:45
- Extra Example 3: Graph the Linear Function10:17
- Extra Example 4: Graph the Linear Function12:28

17m 53s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:15
- Slope Definition 10:18
- Slope Definition 20:40
- Slope1:20
- Positive Slope1:32
- Negative Slope1:39
- Slope of 02:10
- Undefined Slope2:25
- Finding the Slope of a Line3:57
- Example: Using Rise/Run to Find Slope3:58
- Finding the Slope of a Line6:01
- Example: Using Coordinates to Find Slope6:02
- Finding Slope of a Line With Given Coordinates9:00
- Example: Slope of (4,1) and (3, -2)9:01
- Extra Example 1: Find the Slope of the Line10:17
- Extra Example 2: Find the Slope of the Line12:19
- Extra Example 3: Find the Slope of the Line14:54
- Extra Example 4: Find the Slope of the Line16:35

13m 50s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:33
- Direct Variation0:34
- Identifying a Direct Variation0:47
- Steps in Identifying a Direct Variation0:56
- Slope and Direct Variation3:01
- Example: Slope and Direct Variation3:05
- Extra Example 1: Direct Variation6:16
- Extra Example 2: Direct Variation7:14
- Extra Example 3: Graphing Direct Variation8:10
- Extra Example 4: Slope and Direct Variation11:23

17m 32s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:15
- Inequality0:18
- System of Inequalities1:31
- Solution of an Inequality1:50
- Writing an Inequality2:10
- Example: Price p is More than $62:20
- Writing an Inequality3:53
- Example: Wage w is at Least $8.253:54
- Writing a System of Inequalities5:24
- Example: System of Inequalities for Wind Speed5:32
- Writing a System of Inequalities9:03
- Example: Price of a Room in Las Vegas9:04
- Identifying Solutions of an Inequality10:33
- Example: Driver's Permit10:37
- Extra Example 1: Writing Inequalities12:03
- Extra Example 2: Writing a System of Inequalities13:24
- Extra Example 3: Writing Inequalities14:51
- Extra Example 4: Using Inequality to Solve Word Problem15:31

9m 16s

- Intro0:00
- What You'll Learn and Why0:07
- Topics Overview0:08
- Vocabulary0:20
- Addition Property of Equality0:31
- Subtraction Property of Equality0:43
- Example: x > 70:57
- Solving an Inequality by Adding1:33
- Example: Solve x - 8 = 101:37
- Example: Solve x - 8 < 102:05
- Solving an Inequality by Adding2:21
- Example: 2 ≤ t - 52:22
- Example: a - 8 > 152:59
- Solving an Inequality by Subtracting3:14
- Example: How Many Students can Board the Bus?3:22
- Solving an Inequality by Subtracting4:13
- Example: How Many More Tickets can be Sold?4:14
- Extra Example 1: Solve the Inequality5:16
- Extra Example 2: Solve 8 ≥ 3 + m5:52
- Extra Example 3: MP3 Player6:29
- Extra Example 4: Write and Solve an Inequality7:34

12m 15s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:22
- Division Property of Inequality0:23
- Example: 3x > 60:37
- Dividing by a Positive Number1:08
- Example: Hotel Elevator1:11
- Dividing by a Negative Number2:29
- Example: Solve -6x ≥ -182:32
- Example: Suppose x = 23:13
- Dividing by a Negative Number4:58
- Example: Solve -3t ≥ 515:05
- Example: Solve -8m < -565:24
- Extra Example 1: Photo Album5:49
- Extra Example 2: Banquet8:05
- Extra Example 3: Solve -0.5x > 189:24
- Extra Example 4: How Many Crates can the Crane Lift?10:30

14m 33s

- Intro0:00
- What You'll Learn and Why0:07
- Topics Overview0:08
- Vocabulary0:17
- Multiplication Property of Inequality0:18
- Multiplying by a Positive Number1:25
- Example: Write and Solve an Inequality1:28
- Multiplying by a Positive Number3:38
- Example: Write and Solve an Inequality3:39
- Multiplying by a Negative Number5:42
- Example: Solve x/-4 > 285:45
- Example: Solve (-1/2)y < -86:10
- Example: t/-7 < 56:42
- Extra Example 1: Bowling League7:12
- Extra Example 2: Street Performers8:27
- Extra Example 3: Write and Solve the Inequality9:52
- Extra Example 4: Solve and Graph the System of Inequalities11:26

14m 15s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:15
- Inequality0:16
- Properties of Inequality0:27
- Solving Two-Step Inequalities0:37
- Example: Solve -2x - 8 > -140:41
- Example: Solve (x/4) - 7 > 251:40
- Example: Solve -5y + 9 ≤ 542:12
- Writing Two-Step Inequalities3:16
- Example: How Many Pairs of Socks?3:21
- Writing Two-Step Inequalities5:49
- Example: How Many Folders?5:53
- Extra Example 1: Solve 15 < -3 ( x + 1 )7:32
- Extra Example 2: Solve the Inequalities8:43
- Extra Example 3: Muffin10:37
- Extra Example 4: Birthday Party11:51

12m 7s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:26
- Exponent0:29
- Power0:44
- Multiplying Powers with the Same Base1:04
- Example: Multiplying Powers with the Same Base1:07
- Multiplying Expressions with Exponents2:25
- Examples2:26
- Dividing Powers with the Same Base3:24
- Example: Dividing Powers with the Same Base3:25
- Dividing Expression with Exponents3:59
- Example: How Long Sunlight Takes to Reach the Comet4:02
- Dividing Expression with Exponents6:44
- Example: How Long Sunlight Takes to Reach Earth6:45
- Extra Example 1: Multiplying Expressions with Exponents8:22
- Extra Example 2: Dividing Expression with Exponents8:46
- Extra Example 3: How Long Sunlight Takes to Reach Saturn9:12
- Extra Example 4: Sun's Diameter and Earth's Diameter10:34

11m 58s

- Intro0:00
- What You'll Learn and Why0:04
- Topics Overview0:05
- Vocabulary0:15
- Exponent0:18
- Power0:34
- Raising a Power to a Power0:44
- Example: Raising a Power to a Power0:47
- Raising a Power to a Power2:38
- More Examples2:42
- Raising a Product to a Power3:00
- Example: Raising a Product to a Power3:01
- Raising a Product to a Power4:00
- Example: Surface Area of a Plant Cell4:12
- Example: Surface Area of the Moon6:15
- Extra Example 1: Raising Power to a Power8:08
- Extra Example 2: Complete the Inequality Statement8:22
- Extra Example 3: Find the Area of a Square8:51
- Extra Example 4: Find the Area of a Circle10:28

9m 39s

- Intro0:00
- What You'll Learn and Why0:05
- Topics Overview0:06
- Vocabulary0:17
- Square Root0:21
- Roots1:13
- The Root Symbol2:10
- Root Symbols2:11
- Finding Roots of a Number2:41
- Examples2:42
- Simplifying Expressions with Roots4:41
- Example: Simplify the Expression4:42
- Simplifying Expressions with Roots5:42
- Example: Simplify the Expression5:43
- Extra Example 1: Finding Roots of a Number6:36
- Extra Example 2: Simplifying Expressions with Roots7:11
- Extra Example 3: Simplifying Expressions with Roots7:36
- Extra Example 4: Simplifying Expressions with Roots8:34

12m 43s

- Intro0:00
- What You'll Learn and Why0:07
- Topics Overview0:08
- Vocabulary0:23
- Term0:28
- Like Terms0:35
- Combining Like Terms1:18
- Example: 2y + y - 15y1:20
- Example: -x - 5x2:16
- Writing and Simplifying Expressions2:57
- Example: Total Cost of Drinks2:58
- Writing and Simplifying Expressions4:48
- Example: Total Cost of Apples4:49
- Distributing and Simplifying5:42
- Simplify: 4x - 2( x + 6 )5:46
- Simplify: 3( 2y + 2 ) - 4y6:57
- Extra Example 1: Simplify the Expression7:52
- Extra Example 2: Distributing and Simplifying8:18
- Extra Example 3: Writing and Simplifying Expressions9:35
- Extra Example 4: Distributing and Simplifying10:50

18m 35s

- Intro0:00
- What You'll Learn and Why0:06
- Topics Overview0:07
- Vocabulary0:17
- Like Terms0:21
- Distributive Property0:49
- Simplifying Before Solving an Equation1:37
- Example: 8x + 45 - 12x = 91:40
- Example: -15 = 6b + 12 - 3b + 63:25
- Using the Distributive Property4:50
- Example: Haiti Relief Efforts4:51
- Using the Distributive Property7:50
- Example: Amusement Park7:51
- Extra Example 1: Simplify and Solve11:34
- Extra Example 2: Simplify and Solve12:21
- Extra Example 3: Simplify and Solve13:18
- Extra Example 4: Mailing Letters14:53

18m 50s

- Intro0:00
- What You'll Learn and Why0:07
- Topics Overview0:08
- Vocabulary0:26
- Term0:30
- Like Terms0:44
- Variables on Both Sides1:10
- Example: 3x + 24 = 9x1:11
- Example: -7 - 3x = 1 + 5x2:16
- Using the Distributive Property4:01
- Example: Height of Two Plants4:02
- Using the Distributive Property9:01
- Example: Running Laps9:02
- Extra Example 1: Solving Equations with Variables on Both Sides11:59
- Extra Example 2: Solving Equations with Variables on Both Sides12:46
- Extra Example 3: Solving Equations with Variables on Both Sides14:18
- Extra Example 4: Cost of Renting Video15:24

12m 55s

- Intro0:00
- Finding Needed Information1:02
- Ask Yourself1:07
- Example: Finding Needed Information1:25
- Extra Example 1: Finding Needed Information2:36
- Extra Example 2: Finding Needed Information4:10
- Using Mental Math6:10
- Use Mental Math to Eliminate Unreasonable Answers6:16
- Example: Using Mental Math6:47
- Extra Example 1: Simplify Using Mental Math8:54
- Extra Example 2: Mental Math and Total Cost9:36
- Extra Example 3: Account Balance11:15

11m 24s

- Intro0:00
- Working Backward0:06
- Substitute Multiple Choice Answers0:08
- Example: Working Backward0:38
- Extra Example 1: Equivalent Expression2:54
- Extra Example 2: Miles Per Gallon4:13
- Extra Example 3: Miles Per Hour5:14
- Choosing the Process6:12
- Strategies for Choosing the Process6:19
- Example: Dimensions of the Fenced Area6:48
- Extra Example 1: Choosing the Process8:28
- Extra Example 2: Choosing the Process10:01

11m 36s

- Intro0:00
- Eliminating the Answer0:06
- Eliminate Wrong Answers0:07
- Example: Height of a Plant0:49
- Extra Example 1: Distance2:36
- Extra Example 2: Decimal4:11
- Using a Variable4:50
- Variables Represent the Unknown4:51
- Example: Company Logo5:20
- Extra Example 1: Road Trip6:31
- Extra Example 2: Proportion9:03

20m 13s

- Intro0:00
- Eliminating the Answer0:06
- Eliminate Answers and Educated Guess0:07
- Example: Election0:28
- Extra Example 1: Football Kicker2:42
- Extra Example 2: Percent4:09
- Answering the Question Asked6:19
- Answer the Question Correctly6:20
- Example: Inequality6:43
- Extra Example 1: Cost of Cheese8:12
- Extra Example 2: Inequality9:40
- Drawing a Diagram11:35
- Diagrams11:36
- Example: Drawing a Diagram to Show Distance12:03
- Extra Example 1: Drawing a Diagram to Show Distance15:22
- Extra Example 2: Height17:48

For more information, please see full course syllabus of Pre Algebra

3 answers

Last reply by: Shirley Wang

Wed Jul 25, 2018 3:39 PM

Post by Jeff Mitchell on January 7, 2011

I question the results on extra example II. The problem states that there was a decrease of 7 to 2. So, it appears that the original value would have been 7 + 2 or 9. the change was a decrease of 7 which would require the following solution 7/9 * p/100 or 77.7%

~Jeff