Prime and composite

Front

What is a prime number?

Back

A prime number is a number that has ONLY TWO factors: 1 and itself.

Front

What is a composite number?

Back

A composite number is a number that has MORE THAN TWO factors.

Front

Is 21 prime or composite?

Back

Composite, because it has 4 factors: 1, 3, 7, and 21.

Front

Which of the following is a composite number? 2, 3, 4, 5

Back

4, because it has factors 1, 2, and 4.

Front

What are factors?

Back

Factors are numbers that are multiplied together to get another number.

Front

List the first five prime numbers.

Back

2, 3, 5, 7, 11.

Front

List the first five composite numbers.

Back

4, 6, 8, 9, 10.

Front

Is 1 a prime number?

Back

No, 1 is NOT a prime number because it has only one factor.

Front

What is the smallest composite number?

Back

The smallest composite number is 4.

Front

What is the largest prime number less than 20?

Back

The largest prime number less than 20 is 19.