common multiples and common factors

COMMON MULTIPLES

& COMMON FACTORS

Created by

tbonnar.

CH. 1.6 DETERMINING

COMMON MULTIPLES

What are the common multiples of 3 and 4?

Are there any multiples in common?

DETERMINING COMMON MULTIPLES

Multiples of 3 Multiples of 4

1 x 3 = 3 1 x 4 = 4

2 x 3 = 6 2 x 4 = 8

3 x 3 = 9 3 x 4 = 12

4 x 3 = 12 4 x 4 = 16

5 x 3 = 15 5 x 4 = 20

6 x 3 = 18 6 x 4 = 24

7 x 3 = 21 7 x 4 = 28

8 x 3 = 24 8 x 4 = 32

What are the common multiples of 5 and 6? We don’t need to make a chart every time. It is alright to just make a list.

Multiples of 5 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60

Multiples of 6 6, 12, 18, 24, 30, 36, 42, 48, 54, 60

Any multiples in common?

DETERMINING COMMON MULTIPLES

The LCM (Least Common Multiple) is the smallest number that is a multiple of both numbers.

LEAST COMMON MULTIPLE

Multiples of 3 Multiples of 4

1 x 3 = 3 1 x 4 = 4

2 x 3 = 6 2 x 4 = 8

3 x 3 = 9 3 x 4 = 12

4 x 3 = 12 4 x 4 = 16

5 x 3 = 15 5 x 4 = 20

6 x 3 = 18 6 x 4 = 24

7 x 3 = 21 7 x 4 = 28

8 x 3 = 24 8 x 4 = 32

LEAST COMMON MULTIPLE

The LCM (Least Common Multiple) is the smallest number that is a multiple of both numbers.

Multiples of 55, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60

Multiples of 66, 12, 18, 24, 30, 36, 42, 48, 54, 60

LEAST COMMON MULTIPLE

CH. 1.7 DETERMINING

COMMON FACTORS

Recall: every number has factors (that means two numbers that multiply together to equal that number)

Example: Factors of 121 x 12 = 122 x 6 = 123 x 4 = 12

So, 1, 2, 3, 4, 6, and 12 are all factors of 12

DETERMINING FACTORS

If two numbers have the same factors, they are said to have common factors.

One way to determine common factors of numbers is to make lists of the factors.

COMMON FACTORS – MAKING LISTS

Another example:

COMMON FACTORS – MAKING LISTS

COMMON FACTORS – MAKING LISTS

What does this Venn Diagram show us?

What can we learn about common factors from it?

COMMON FACTORS – USING VENN DIAGRAMS