GCF prove-it

GCF stands for:

• Greatest center formation

• Greatest common factor

• Good call foul

• Greatest center factor

Check all that are factor pairs for 21:

• 3 and 7

• 21 and 1

• 11 and 10

• 0 and 21

81 is a prime number.

• True

• False

56 is a composite number.

• True

• False

The GCF of 24 and 18

• 3

• 4

• 6

• 8

What is the GCF of 45 and 55?

• 5

• 11

• 9

• 2

What is the GCF of 120 and 110?

• 15

• 25

• 5

• 10