Educator

Prime Factorization

• Learn the Divisibility Rules. They will be useful in many situations; anywhere from finding prime factorization to working with fractions.
• Divisibility Rules
• You can divide by these following numbers when…
• 2: any even number, a number ending in 0, 2, 4, 6, or 8
• 3: the sum of the digits is divisible by 3
• 4: the last two digits are divisible by 4
• 5: the number ends in 0 or 5
• 6: both 2 and 3 work
• 9: the sum of the digits is divisible by 9
• 10: the number ends in 0
• A factor is a whole number that divides a nonzero whole number with no remainder.
• A prime number is a number greater than 1 with exactly two factors, 1 and itself.
• Remember that before you decide a number is prime; make sure to check if the number is divisible by 3 or 7. For example, 51 and 57 seem to be prime numbers, but are not!
• A composite number is a whole number greater than 1 with more than two factors.
• Prime Factorization represents a composite number written as a product of prime numbers.
• When writing the prime factorization, order the factors in ascending order and use exponents when possible.