For more information, please see full course syllabus of Basic Math

For more information, please see full course syllabus of Basic Math

## Discussion

## Study Guides

## Practice Questions

## Download Lecture Slides

## Table of Contents

## Transcription

## Related Books

### Adding and Subtracting Fractions with Same Denominators

#### Related Links

- Numerator: The top number of a fraction
- Denominator: The bottom number of a fraction
- When we add fractions, we want the fractions to have the same denominator, or a common denominator
- Add the numerators together and keep the denominator the same

### Adding and Subtracting Fractions with Same Denominators

**4**)/(

**7**)]

**5**)/(

**9**)]

**7**)/(

**10**)]

**3**)/(

**4**)]

**5**)/(

**7**)]

- [12/30] + [18/30] = [30/30]
- [30/30] = 1

**4**)/(

**15**)]

**4**)/(

**17**)]

**24**)/(

**45**)]

**28**)/(

**35**)]

*These practice questions are only helpful when you work on them offline on a piece of paper and then use the solution steps function to check your answer.

Answer

### Adding and Subtracting Fractions with Same Denominators

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

- Intro 0:00
- Same Denominator 0:11
- Numerator and Denominator
- Example: 2/6 + 5/6
- Extra Example 1: Add or Subtract the Fractions 2:02
- Extra Example 2: Add or Subtract the Fractions 2:45
- Extra Example 3: Add or Subtract the Fractions 3:17
- Extra Example 4: Add or Subtract the Fractions 4:05

### Basic Math Online Course

### Transcription: Adding and Subtracting Fractions with Same Denominators

*Welcome back to Educator.com.*0000

*This lesson, we are going to add and subtract fractions with common denominators.*0002

*Right here, this is a fraction; the top number, 1, is called the numerator.*0013

*This number right here is called the numerator.*0022

*This bottom number, the 2, is called the denominator.*0029

*When we add fractions, I have 2/6 plus 5/6; I am adding two fractions together.*0042

*Let's look at their denominators.*0050

*The denominator for this fraction is a 6; the denominator for this fraction is a 6.*0052

*Once the denominators are the same, now they have a common denominator, then I can add the fractions.*0059

*This 2/6 plus 5/6, I am going to add the numerators together.*0068

*The numerator for this fraction is 2; the numerator for this fraction is a 5.*0075

*2 plus 5; that is going to become my numerator for my answer*0080

*For my denominator, it is going to stay the same as a 6.*0088

*2/6 plus 5/6 is 7/6.*0096

*Again the denominators for each fraction has to be the same.*0100

*Then I take my numerators; I add them together; 2 plus 5 is 7.*0105

*I do not add my denominators; my denominator has to stay the same as 6.*0111

*2/6 over 5/6 is going to equal 7/6.*0116

*Here we are subtracting these fractions, 7/8 minus 1/8.*0124

*The denominator is the same; here is an 8 here.*0130

*The denominator for this fraction is an 8.*0133

*Therefore I can go ahead and subtract them.*0136

*I am going to do 7 minus 1 which is 6.*0139

*I take my denominator; that is going to stay the same.*0147

*Do not subtract your denominators; it is 7 minus 1 which is 6.*0150

*My denominator must stay the same as 8; 7/8 minus 1/8 is 6/8.*0156

*My next example, 9/10 plus 3/10.*0166

*I am going to take my numerators, add them together.*0174

*It is 9 plus 3 which is 12 over... do not add your denominators.*0177

*It is going to stay the same as a 10.*0186

*9/10 plus 3/10 is going to equal 12/10.*0189

*Again 11/20 plus 9/20, same denominator.*0199

*I take 11, add it 9; I get 20 over... 20 plus 20?*0206

*No, you do not add them together; the denominators are 20 here.*0216

*The denominator for this one has to also be 20.*0221

*Let's look at this fraction right here; my answer is 20/20.*0225

*20/20, if the numerator and the denominator are the same, this is equal to 1.*0231

*My answer would just be 1.*0240

*The fourth example when we are adding and subtracting fractions, 23/95 plus 6/95.*0247

*Whenever I add or subtract fractions, I have to make sure that the denominators for both fractions are the same.*0258

*In this case, the denominator is 95; for this one, the denominator is 95.*0265

*Since they are the same, I can go ahead and add the fractions together.*0270

*I take the numerators which is 23 and 6; I am going to add them together.*0276

*23 plus 6 is 29.*0282

*For my denominator, denominator here is 95; here is 95.*0287

*For my answer, the denominator also has to be a 95.*0293

*You do not add the denominators together; the denominator stays the same as 95.*0298

*23/95 plus 6/95 is going to equal 29/95.*0304

*That is it for this lesson; thank you for watching Educator.com.*0313

0 answers

Post by Amanda Rimeikis on February 15, 2017

Great teachings! I was hoping on the last extra example 4: you would explain the other strategy that you mentioned, rather than the LCM OR LCD, with 23/95 + 4/5... when you said you can divide 95 by 5, since its a multiple... so what do you do in that case?

0 answers

Post by Ana Chu on February 4, 2014

Thank you, really good!