Prime factors
for 5th grade
Identify the prime factors of each number up to 99
Identify the prime factors of numbers to 99
Factors are numbers that divide into a number without a remainder. The factors of 12 are 1, 2, 3, 4, 6 and 12. Prime factors are the factors of a number that are prime numbers (numbers that can only be divided evenly by 1 and themselves).
To find the prime factors of a number, first list all of it's factors, then decide which of them are prime. Express the number as a product of it's prime factors.
So, in the first question from the lesson we have the number 6. The factors of 6 are 1, 2, 3 and 6, and the prime factors are 2 and 3 (1 is not considered a prime number).
Starting with the smallest prime factor, divide the original number by that value, and continue to do so until the result is no longer divisible by that prime factor without a remainder. Move to the next largest prime factor and continue until you have the original number expressed as a product of it's prime factors.
Prime factors of 6: 2 x 3
Prime factors of 20: 2 x 2 x 5
Prime factors of 48: 2 x 2 x 2 x 2 x 3
Prime factors of 21: 3 x 7
Below is a table showing the first 6 question answer pairs for the topic "Prime factors" as used in the lessons for this topic. Our games and tests for the topic use these 6 items plus 10 additional question answer pairs.
The topic "Prime factors" is in the category Multiply + Divide for 5th grade (ages 10 to 11).
Revise 'Prime factors' with one of our games for 5th grade
Each of our math topics for elementary are made up of between 6 and 20 question and answer pairs (both the written form and a robot voice speaking those questions and answers). Each topic can be used with all the activities on the site.
Counting * Comparing numbers * Pattern * Place value * Addition * Subtraction * Add + Subtract * Multiplication * Division * Multiply + Divide * Fractions * Decimals * Ratio + proportion * Measurements * Shapes * Position + Direction * Statistics * Algebra *
