LCM/GCF Practice

To break down 2 numbers using prime factorization trees and find what they have in common is ...

To find the least common multiple, LCM, you can:

• use prime numbers

• skip count

• use the times table chart

• subtract by 10

What is the LCM of 12 and 10 (skip count)?

• 40

• 2

• 60

• 120

What is the prime factorization of 30 (tree)?

• 2 x 15

• 1 x 30

• 3 x 15

• 2 x 3 x 5

What is the GCF of 12 and 10 (prime factorization tree)?

• 10

• 2

• 6

• 5

What is the least common multiple (LCM) of 8 and 5?

• 50

• 40

• 5

• 8

What is the prime factorization of 42 (tree)?

• 2 x 28

• 1 x 42

• 2 x 3 x 7

• 6 x 7

What is the GCF (tree) of 35 and 42?

What is the first prime number?

• 1
• 2
• 3
• 5

Tags

CCSS.4.OA.B.4

Is 11 prime or composite?

• Prime

• Composite