Worked Example 1
Factor Pairs
Find all the factor pairs of 36.
- 11 × 36 = 36 and 2 × 18 = 36
- 23 × 12 = 36 and 4 × 9 = 36
- 35 is not a factor. 6 × 6 = 36.
- 4After 6, the pairs repeat.
Answer: 1 × 36, 2 × 18, 3 × 12, 4 × 9, 6 × 6
Florida Grade 4 Math · Algebraic Reasoning
MA.4.AR.3.1: Factors, Prime, and Composite Numbers
What this Grade 4 benchmark means, worked examples, common mistakes, and a free printable worksheet.
Created by a Florida mom · Published by Tropical Learning LLC
What Is Benchmark MA.4.AR.3.1?
Students find all the factor pairs of a whole number from 0 to 144 and decide whether it is prime, composite, or neither.
A prime number has exactly two factors: 1 and itself (like 7). A composite number has more than two factors (like 12). The numbers 0 and 1 are neither prime nor composite. Divisibility rules help: even numbers are divisible by 2, and if the digits add to a multiple of 3, the number is divisible by 3.
Official benchmarkDetermine factor pairs for a whole number from 0 to 144. Determine whether a whole number from 0 to 144 is prime, composite or neither.
On the FAST test: part of the Grade 4 reporting category Number Sense and Operations with Whole Numbers, which is about 31–37% of the test.
Worked Examples
Worked Example 2
Prime or Composite?
Is 51 prime or composite?
- 1The digits add to 5 + 1 = 6, which is a multiple of 3, so 3 is a factor.
- 23 × 17 = 51
- 351 has factors other than 1 and 51.
Answer: Composite
Common Mistakes to Watch For
Calling 1 a prime number
Wrong:1 is prime because it can only be divided by 1 and itself.
A prime has exactly two different factors. 1 has only one factor, so it is neither prime nor composite.
Thinking all odd numbers are prime
Wrong:51 is prime because it is odd.
Many odd numbers are composite: 51 = 3 × 17, and 9 = 3 × 3.
Helpful Math Tip
Make arrays with small objects. If a number of objects can only make one long row (and its turn), the number is prime.
Related Grade 4 Skills
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Start Practicing FreeIndependent Educational Platform. FastChomp is published by Tropical Learning LLC and is not affiliated with, sponsored by, or endorsed by the Florida Department of Education. FAST and Star assessment names are referenced for informational purposes only. FastChomp practice questions are original educational materials, not official Florida FAST assessment questions.