Prime numbers

All prime numbers are odd numbers.

• True

• False

Answer explanation

There is only one even prime number...2!

Tags

CCSS.4.OA.B.4

There are ten prime numbers less than 30

• True

• False

Answer explanation

These are: 2, 3, 5, 7, 11, 13, 17, 19, 23, and 29

Tags

CCSS.4.OA.B.4

All prime numbers have exactly two factors.

• True

• False

Answer explanation

All prime numbers can be divided by themselves and 1. These are the two factors

Tags

CCSS.4.OA.B.4

If you add two prime numbers, it always makes an even number.

• True

• False

Answer explanation

2 + 3 = 5

Don't forget that 2 is a prime number!

Tags

CCSS.3.OA.D.9

Every number next to a multiple of 6 is a prime number

• True

• False

Answer explanation

48 is a multiple of 6, but 49 is not a prime number, because 7x7=49

Tags

CCSS.4.OA.B.4

Every two-digit prime number is next to a multiple of 6.

• True

• False

Answer explanation

Yeah, I checked. Weirdly enough, it's true.

Tags

CCSS.4.OA.B.4

Every two-digit multiple of 6 is next to a prime number.

• True

• False

Tags

CCSS.4.OA.B.4

There is only one two-digit prime number that starts with a 6_.

• True

• False

Answer explanation

There are two prime numbers in the 60's: 61 and 67

Tags

CCSS.4.OA.B.4

1 is not a prime number.

• True

• False

Answer explanation

Prime numbers have only two factors. The number 1 only has one factor - itself!

Tags

CCSS.4.OA.B.4

All two-digit prime numbers end in either _1, _3, _7, or _9

• True

• False

Answer explanation

It can't be an even number, and anything that ends in 5 can be divided by 5. This leaves just 1, 3, 7, and 9 as the possible last digits.

Tags

CCSS.5.OA.B.3