Explain why 21 is composite.

Q: What will my child learn in "Explain why a number is prime or composite"?

State the factors you found or did not find. This 5th Grade Math lesson builds the skill Find factors and use divisibility rules with a concept card and practice.

Q: What grade level is "Explain why a number is prime or composite" for?

"Explain why a number is prime or composite" is a 5th Grade Math lesson in the Factors and multiples unit, designed for students around ages 10-11.

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Sparq is a safe AI tutor that gives kid-friendly hints and explains Explain why a number is prime or composite step by step, helping students learn without just giving away the answer.

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Question

Explain why 21 is composite.

Accepted Answer

21 is composite because it has factors 1, 3, 7, and 21.