Page 139 - Math Course 1 (Book 1)

Greatest Common Factor (GCF)

Find the GCF of 12, 48, and 72. The common prime factors are 2, 2, and 3.

12: 2 • 2 • 3 Prime Factors Prime Factors
48: 2 • 2 • 2 • 2 • 3 of 12 of 48
72: 2 • 2 • 2 • 3 • 3 2
2 2
3 2
The GCF of 12, 48, and 72 is Prime Factors
Answer
2 • 2 • 3 or 12. of 72 3

BAKE SALE Your Turn!
Parents donated 150 chocolate chip cookies and
120 molasses cookies for a school bake sale. If the
cookies are arranged on plates, and each plate has Find The GCF
the same number of chocolate chip cookies and
the same number of molasses cookies, what is the Find the GCF of 18 and 30.
largest number of plates possible?
A. 3
Find the GCF of 150 and 120. B. 6
150: 2 • 3 • 5 • 5 C. 2
120: 2 • 2 • 2 • 3 • 5 D. 9

The common prime factors are 2, 3, and 5.
The GCF of 150 and 120 is 2 • 3 • 5 or 30. Answer

Answer So, 30 plates are possible. Find the GCF of 24 and 32.

A. 2
B. 6
C. 8
D. 12
BAKE SALE
Parents donated 150 chocolate chip cookies and Answer
120 molasses cookies for a school bake sale. How
many chocolate chip and molasses cookies will be
on each plate? Find the GCF of 30, 42, and 60.

Chocolate chip: 150 ÷ 30 = 5 A. 6
Molasses: 120 ÷ 30 = 4 B. 3
C. 12
D. 2
So, each plate will have 5
Answer chocolate chip cookies
and 4 molasses cookies. Answer

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