This document provides instruction on finding the least common multiple (LCM) of two or more numbers using different strategies. It explains that the LCM is the smallest number that is a multiple of both/all numbers. Three methods are described: 1) listing the multiples of each number and finding their common multiples, 2) using prime factorization and factor trees, and 3) using the Lemon CAKE method which involves setting up a division problem to systematically find the LCM. Examples of each method are worked through.

1. Fill in the chart above.
X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9
2
3

2. Learning Target:
Students will learn how to find the
least common multiple (LCM) of two or
more numbers and they will learn the
different strategies for doing so.

3. These are the multiples of 2 and 3.
(always start by multiplying by 1)
The first three common multiples
are 6, 12, 18.
The least common multiple
(LCM) is 6.
X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9
2 2 4 6 8 10 12 14 16 18
3 3 6 9 12 15 18 21 24 27

4. Find two common multiples of the
numbers.
6, 18

5. Answer:
6, 18
Common multiples: 18, 36

6. Methods of finding the LCM
1. List the multiples of each number
2. Prime Factorization
- Factor Tree
3. Lemon CAKE

7. Find the LCM of 3, 5.
1. List the multiples of each number
(do two multiples at a time)
3: 3, 6, 9, 12, 15
5: 5, 10, 15, 20
LCM: 15

8. Find the LCM of 8, 10.
2. Prime Factorization
- Factor Tree
Prime factorization of
8: 2, 2, 2
10:2, 5
LCM: 2 x 2 x 2 x 5 = 40

9. Find the LCM of 50, 90.
3. Lemon CAKE
2 50 90
5 25 45
5 9 = 450
LCM: 2 x 5 x 5 x 9 = 450

10. Lemon CAKE method
you do the same steps as the CAKE
method except that you multiply the
left side and the bottom side of the
cake (which makes a L shape) to find
the LCM.

11. Find the LCM of the numbers.
8, 14
9, 15

12. Answers:
8, 14
LCM: 56
9, 15
LCM: 45

13. Can you find the least common
multiple (LCM) of two or more
numbers?