Practice Composite Numbers in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Integers greater than 1 that can be expressed as a product of two smaller positive integers; they are the opposite of primes.

Numbers that can be built by multiplying smaller numbers together.

Example 1

easy
Determine whether 91 is prime or composite. If composite, find a factor pair.

Example 2

medium
List all composite numbers between 20 and 35, and for each, give one non-trivial factor pair.

Example 3

easy
Is 1 composite? Is 4 composite? Is 2 composite? Explain each briefly.

Example 4

medium
How many composite numbers are there from 1 to 20? List them and explain why each is composite.