LCM and GCF review

What is the GCF of 14 and 28?

• 7

• 14

• 21

• 28

How do you find the LCM of two numbers?

• List the multiples of each number and find the smallest common multiple.

• Multiply the two numbers and divide by their GCD.

• Add the two numbers together to get the LCM.

• Find the largest number that divides both numbers.

What is the GCF of 9 and 27?

• 3

• 6

• 9

• 12

What is the LCM of 5 and 10?

• 5

• 10

• 15

• 20

What is the LCM of 8 and 12?

• 20

• 22

• 24

• 30

What is the GCF of 10 and 50?

• 5

• 10

• 15

• 20

What is the GCF of 12 and 28?

• 2

• 4

• 6

• 8

How do you find the GCF of two numbers?

• List the factors of each number and find the largest common factor.

• Multiply the two numbers together and divide by their smallest number.

• Add the two numbers together and find the largest factor of the sum.

• Subtract the smaller number from the larger number until you reach zero.

Define LCM (Least Common Multiple).

• The largest multiple that is exactly divisible by two or more numbers.

• The smallest multiple that is exactly divisible by two or more numbers.

• The sum of the multiples of two or more numbers.

• The difference between the largest and smallest multiples of two or more numbers.

What is the GCF of 21 and 42?

• 14

• 21

• 28

• 35