Prime and Composite

Sort numbers as prime, composite, or neither.

Warm-up, learn, try it together, practice, then a quick check. About 15 minutes.

What children learn in Level 51

Some numbers have only one factor pair. 7 is only 1 times 7. A number with exactly two factors, 1 and itself, is prime.
12 has more factor pairs: 1 times 12, 2 times 6, and 3 times 4. A number with more than two factors is composite.
1 is special: its only factor is 1. It isn't prime or composite. It's neither!
2 is the only even prime. Every other even number has 2 as a factor, so it's composite.

Georgia's K-12 Mathematics Standards:

4.PAR.3.4 — Identify composite numbers and prime numbers and explain the relationship with the factor pairs.