Calculating the greatest common factor (GCF)

 Find the GCF of each set of numbers. 
14, 56, 63

• 9
• 4
• 7
• 8

Find the GCF of 6 and 24. 

• 2
• 3
• 1
• 6

Bill cut out 6 squares and 8 circles. He divided the cutouts into groups so that the same number of squares and circles were in each group. What is the greatest number of groups he could have made?

• 2

• 3

• 4

• 5

Find the greatest common factor of 20 and 30

• 2

• 5

• 10

• 15

Answer explanation

What is the greatest common factor of 14 and 21?

• 35

• 42

• 7

• 1

What are the common factors of 24 and 36?

• 1, 2, 3, 4, 6, 12

• 1, 3, 4, 6

• 2, 4, 12

• 1, 2, 3, 4, 5, 12

What is the GCF of 35 and 21?

• 3

• 7

• 5

• 21

Jars of pickles can be mailed in large or medium boxes. A large box can hold 21 jars of pickles. A medium box can hold 16 jars of pickles. There are 1193 jars of pickles to be mailed.

How many large and medium boxes are needed if every box must be full?

• 53 large, 5 medium boxes

• 54 large, 4 medium boxes

• 56 large, 2 medium boxes

• 56 large, 1 medium boxes

What is the Greatest Common Factor of 9 and 36

• 3

• 6

• 9

• 12

• Not Given

Chad is setting out some snacks for friends he is having over. He has 27 crackers and 36 slices of cheese. If he wants each plate to be identical, with no food left over, what is the greatest number of plates Chad can prepare?

• 6 plates

• 8 plates

• 9 plates

• 4 plates