The document explains the concept of lowest common multiples (LCM) and provides a method to calculate it by listing multiples of two numbers. Using the example of the numbers 60 and 72, it demonstrates that their LCM is 360. It also includes exercises for finding the LCM of additional pairs of numbers and reinforces the definitions learned.

1. Prime Factorization
NUMBERS AND
NUMBER SENSE

2. PRIME FACTORIZATION
 When we study multiplication there are certain terms that
are associated with it.These terms include:
Factors
Multiples
Highest Common Factors (HCF)
Lowest Common Multiples (LCM)
In this video we will discuss Lowest Common
Multiples.

3. PRIME FACTORIZATION
LOWEST COMMON MULTIPLE
 Just like with HCF, here also you are comparing two numbers.
To find the lowest common multiple of these numbers you do
the following:
1. Find the first 6 or 7 multiples of the 1st number by
multiplying it by counting numbers (1, 2, 3, 4, 5, 6……)
2. Do the same thing for the 2nd number
3. Find the smallest number that is common in both lists
Let’s look at a live illustration.

4. PRIME FACTORIZATION
LOWEST COMMON MULTIPLE
Let’s compare the two numbers 60 and 72.We have
to find their LCM
Multiples of 60: 60, 120, 180, 240, 300, 360, 420
Multiples of 72: 72, 144, 216, 288, 360, 432
The number 360 is the lowest multiple found in both
lists; therefore the LCM of 60 and 72 is 360.

5. PRIME FACTORIZATION EXERCISE
 Find the lowest common multiple of the numbers below:
24 and 32 21 and 42 33 and 110
Draw the table and fill in the answers either in your book or
on the computer.
24 32 21 42 33 110

6. PRIME FACTORIZATION EXERCISE
 Did you get the responses in RED below?
24 and 32 21 and 42 33 and 11
LCM = 96 LCM = 42 LCM = 33
YOU ROCK!
24 32
24 32
48 64
72 96
96 128
21 42
21 42
42 84
63 126
84 168
33 11
33 11
66 22
99 33
132 44

7. PRIME NUMBERS RECAP
 In this lesson you learned:
The definition of Lowest Common
Multiple
How to find the lowest common
multiple of two numbers
GREATWORK!