L e a s t C o m m o n M u l t I p l e
Multiple What is a ? The product you get when a number is multiplied by another number. Example: Multiples of 6 – 6, 12, 18, 24, 30,... (6 x 1) (6 x 2) (6 x 3) (6 x 4) (6 x 5) (9 x 1) (9 x 2) (9 x 3) (9 x 4) (9 x 5) Multiples of 9 - 9, 18, 27, 36, 45,...
How many total squares are pictured?? 16 12 Multiples of 4 are 4, 8, 12, 16….. 8 4
Smallest multiple they both have. 6 6, 12, 18, 24, 30, 36 LCM = 24 8 Let’s put LEAST COMMON MULTIPLE in our own words Smallest multiple they both have. Example: 6 6, 12, 18, 24, 30, 36 LCM = 24 8 8, 16, 24, 32, 40, 48
Why don’t we try a couple together! 4 4, 8, 12, 16, 20, 24 LCM = 20 10 10, 20, 30, 40, 50, 60 12 12, 24, 36, 48, 60 LCM = 36 9 9, 18, 27, 36, 45
Let’s use repeated division! There is another way!! Let’s use repeated division!
Find the LCM of 20 and 30. METHOD 2 Repeated Division 10 20 30 20 30 10 ● 2 ● 3 = 60 2 3 The Least Common Multiple (LCM) is 60
Find the LCM of 4 and 10. METHOD 2 Repeated Division 2 4 10 4 10 2 ● 2 ● 5 = 20 2 5 The Least Common Multiple (LCM) is 20
Find the LCM of 12 and 18. METHOD 2 Repeated Division 2 12 18 12 18 2 ● 3 ● 2 ● 3 = 36 3 6 9 2 3 The Least Common Multiple (LCM) is 36
What if there are 3 numbers? Find the LCM of 4,6,and 8 4 4, 8, 12, 16, 20, 24 6 6, 12, 18, 24, 30, 36 8 8, 16, 24, 32, 40, 48 LCM = 24
Find the LCM of 4, 6 and 8. METHOD 2 Repeated Division 2 4 6 8 **Keep dividing until all bottom numbers are only divisible by one** 2 4 6 8 2 ● 2 ● 1 ● 3 ● 2 = 24 2 2 3 4 Just bring down the number that is not being divided 1 3 2 The Least Common Multiple (LCM) is 24
Find the LCM of 4, 6 and 12. METHOD 2 Repeated Division 2 4 6 12 **Keep dividing until all bottom numbers are only divisible by one** 2 4 6 12 2 ● 3 ● 2 ● 1 ● 1 ● 1 = 12 3 2 3 6 Just bring down the number that is not being divided 2 2 1 2 1 1 1 The Least Common Multiple (LCM) is 12
ASSIGNMENT! Finding the LCM WS Yeah! Try your best! You can do it!!
It's your turn !!! 7 7, 14, 21, 28, 35, 42 4 4, 8, 12, 16, 20, 24 , 28, 32, 36 LCM = 28 20 20, 40, 60, 80, 100 LCM = 60 30 30, 60, 90, 120, 150