Prime, Composite Numbers, and Multiples Worksheets
Use factor pairs to distinguish prime and composite numbers.
Teaching notes for parents and teachers
How to teach it
Build arrays or list factor pairs systematically. Then connect multiplication facts to tests for multiples.
Example to work through together
Use the model below as you explain the example. Have your student point to the quantities as you discuss them.
12 = 1 × 12 = 2 × 6 = 3 × 4
A factor pair other than one times the number proves that the number is composite. To call a number prime, check that no such pair exists.
Ask your student
How many positive factors does a prime number have?
If your student needs help
If the student calls one prime, compare its single positive factor with the definition.
Choosing and using the worksheet
Each sheet contains three prime-or-composite questions and three multiple checks. Numbers to classify or test range from 2 through 100. Multiple checks use divisors from 2 through 9.
Make a practice set
Select the worksheet, answer key, or both. When both are selected, the answer key prints after the questions. Keep it separate if you want your student to work independently.
After your student finishes
Ask for evidence: a factor pair, a divisor check, or a multiplication fact. An odd number is not automatically prime.
Word problemsFactors and Factor Pairs Word Problems
Arrange counters into equal rows with none left. Find every possible count per row and check that the factor list is complete.
4 problems · Answer key included
Calculation practiceMissing Factors and Dividends
Use related multiplication and division facts to find the missing number.
6 problems · Answer key included
More about numbers · Grade 4 worksheets
Grade 4 selected skill connection: 4.OA.B.4. See the Common Core standards for this grade. This worksheet does not cover every requirement in the standard.