Primes and Composites

Numbers whose only factors are 1 and itself

• Whole Number

• Decimal Number

• Prime Number

• Composite Number

Answer explanation

A number with only 2 factors, 1 and itself, is a PRIME number

Which of the following statements are TRUE?

• One is a prime number

• One is a composite number

• One is neither prime nor composite.

Answer explanation

1 and 0 are NOT prime or composite. They are NEITHER.

A number that has 3 or more factors

• Whole Number

• Decimal Number

• Prime Number

• Composite Number

Answer explanation

A composite number has 3 or more factors.

Are all even numbers composite numbers?

• Yes

• No

Answer explanation

2 is an even number. 2 is also a prime number.

Are ALL odd numbers prime numbers?

• Yes

• No

Answer explanation

Some odd numbers are prime, but not all. Numbers like 15, 21, and 27 are composite numbers.

If the last digit of a number is 5, then the number is divisible by:

• 2

• 3

• 6

• 5

Answer explanation

Numbers that end in 0 or 5 are always divisible by 5

Out of the ten numbers listed below, how many of them are prime numbers?

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

• two

• three

• four

• five

Which of the following statements is NOT TRUE?

• One is the smallest odd prime number

• Two is the only even prime number

• Three is the smallest odd prime number

• Two is the smallest prime number

Noah wrote a composite odd number that has a digit 4 in the tens place. Which of the following numbers could be the number that Jake wrote?

• 41

• 43

• 47

• 49

Which one of the following numbers is a prime number?

• 21

• 23

• 25

• 27