LCM

Warm Up Find the Greatest Common Factor: 40 and 32 28 and 42

40 32 28 42 18 24 36

Warm Up Answers 40 and 32 = 8 28 and 42 = 14 18, 24, and 36 = 6

LCM Notes #7 Objective: As a learner I will be able to… Define Multiple and Least Common Multiple. Find LCM for 2 or more numbers using different methods.

Vocabulary Multiple: The product of a number. (“Answer” to that numbers time tables) Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24 Multiples of 12: 12, 24, 36, 48, 60, 72, 84 Least Common Multiple (LCM): The smallest number that is the multiple of two or more given numbers.

Finding Multiples: A multiple of 7 is 14 (7 x 2 = 14 so 14 is a multiple of 7) Find the first five multiples: 6: 9:

LCM – Listing Method List the multiples of each number. Find the smallest one in common. Find the LCM of 3 and 7: 3: 7:

LCM – Listing Method Ex: Use the listing method to find the LCM of 8 and 12. 8: 12:

LCM – Prime Factorization Method Find the prime factorization of each number. Look for common prime numbers. Find the GCF. Multiply the GCF by the remaining factors.

LCM – Prime Factorization Method Use the Prime Factorization method to find the LCM of 6 and 8. 6 8

LCM – Prime Factorization Method Use the Prime Factorization Method to find the LCM of 9 and 15. 9 15

Practice Dan goes to the health club every 4 days. His sister Nancy goes there every 6 days. Dan and Nancy both went to the health club today. When will they both go there on the same day again? Answer: In 12 Days

Practice Find the LCM of 9, 12, and 18 Answer: 36

Practice A new clothing store was having a grand opening sale. Every 8th customer got a free t-shirt and every 18th customer got a free hat. Who was the first customer to receive both items for free? Answer: Customer 72