WHAT ARE PRIMES?

Discover prime numbers - numbers with exactly two factors.

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WHAT IS A PRIME NUMBER?

A prime number has exactly two factors: 1 and itself. That means no other number divides into it evenly. 7 is prime because only 1 × 7 = 7. But 6 is not prime because 1 × 6, 2 × 3 all make 6 - it has four factors.

Is 7 prime?

1Factors of 7: only 1 and 7

2Exactly 2 factors > Prime!

= yes

Is 6 prime?

1Factors of 6: 1, 2, 3, 6

2More than 2 factors > Not prime

= no

LEADER TIP

Every number is either prime or composite (except 1). Use factor rectangles - primes can only make a single row.

PRACTICE WITH THESE GAMES

Prime Hunt

Factor Finder

Want more practice? Generate printable worksheets with similar problems.

Go to Worksheets

CONTINUE WITH:

Sieve of Eratosthenes

Factors & Primes

WHAT ARE PRIMES?

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WHAT ARE PRIMES?