Common factors and multiples can find by making a list of factors and multiples of those numbers and separating the common numbers between them.

## How to find common factors of two numbers?

To find the common factors of two numbers first we make a list of factors(no. that divide)of both numbers and then search for the common numbers between both. These common numbers are known as common factors.

Here we are discussing common factors by some examples for better understanding:

### Common factors of 20 and 24

First, we find the factors of 20 and 24 then we find the common factors between them.

Factors of 20 are **1**, **2**, **4**, 5, 10, and 20.

Factors of 24 are **1**, **2**, 3, **4**, 6, 8, 12, and 24.

Common factors of 20 and 24 are 1, 2, and 4.

### What factors do 6 and 4 have in common?

First, we find the factors of 6 and 4 then we find the common factors between them.

Factors of 6 are **1**, **2**, 3, and 6.

Factors of 4 are **1**, **2**, and 4.

Common factors of 6 and 4 are 1, and 2.

### What factors do 18 and 32 have in common?

First, we find the factors of 18 and 32 then we find the common factors between them.

Factors of 18 are **1**, **2**, 3, 6, 9, and 18.

Factors of 32 are **1**, **2**, 4, 8, 16, and 32.

Common factors of 18 and 32 are 1, and 2.

## How to find common multiples of two numbers?

To find the common multiples of two numbers first we make a list of multiples of both numbers and then search for the common numbers between them. These common numbers are known as common multiples.

Here we are taking some examples of common multiples for better understanding:

### Common multiples of 6 and 8

First, we find the multiples of 6 and 8 then we find common multiples between them.

Multiples of 6 are 6, 12, 18, **24**, 30, 36, 42, **48**, 54, 60, 66, **72**,...

Multiples of 8 are 8, 16, **24**, 32, 40, **48**, 56, 64, **72**, 80, 88, 96,...

Common multiples of 6 and 8 are 24, 48, 72,...

### Common multiples of 4 and 6

First, we find the multiples of 4 and 6 then we find common multiples between them.

Multiples of 4 are 4, 8, **12**, 16, 20, **24**, 28, 32, **36**, 40, 44, **48**,...

Multiples of 6 are 6, **12**, 18, **24**, 30, **36**, 42, **48**, 54, 60, 66, 72,...

Common multiples of 4 and 6 are 12, 24, 36, 48,...

### Least common multiples of 4 and 9

First, we find the multiples of 4 and 9 then we find the least*(smallest)* common multiples between them.

Multiples of 4 are 4, 8, 12, 16, 20, 24, 28, 32, **36**, 40, 44, 48,...

Multiples of 9 are 9, 18, 27, **36**, 45, 54, 63, 72, 81, 90, 99, 108,...

The Least(lowest)Common multiple of 4 and 9 is 36.

### Common multiples of 6 and 9

First, we find the multiples of 6 and 9 then we find common multiples between them.

Multiples of 6 are 6, 12, **18**, 24, 30, **36**, 42, 48, **54**, 60, 66, **72**,...

Multiples of 9 are 9, **18**, 27, **36**, 45, **54**, 63, **72**, 81, 90, 99, 108,...

Common multiples of 6 and 9 are 18, 36, 54, 72,...

### Common multiples of 4 and 5

First, we find the multiples of 4 and 5 then we find common multiples between them.

Multiples of 4 are 4, 8, 12, 16, **20**, 24, 28, 32, 36, **40**, 44, 48,...

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

Common multiples of 4 and 5 are 20, 40,...

### Common multiples of 3 and 5

First, we find the multiples of 3 and 5 then we find common multiples between them.

Multiples of 3 are 3, 6, 9, 12, 15, 18, 21, 24, 27, **30**, 33, 36,...

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

Common multiples of 3 and 5 are 30...

### Common multiples of 2 and 3

First, we find the multiples of 2 and 3 then we find common multiples between them.

Multiples of 2 are 2, 4, **6**, 8, 10, **12**, 14, 16, **18**, 20, 22, **24**,...

Multiples of 3 are 3, **6**, 9, **12**, 15, **18**, 21, **24**, 27, 30, 33, 36,...

Common multiples of 2 and 3 are 6, 12, 18, 24,...

### What are the common multiples of 8 and 12?

First, we find the multiples of 8 and 12 then we find common multiples between them.

Multiples of 8 are 8, 16, **24**, 32, 40, **48**, 56, 64, **72**, 80, 88, **96**,...

Multiples of 12 are 12, **24**, 36, **48**, 60, **72**, 84, **96**, 108, 120, 132, 144,...

Common multiples of 8 and 12 are 24, 48, 72, 96,...

### What are the least common multiples of 8 and 12?

First, we find the multiples of 8 and 12 then we find the least*(smallest) *common multiples between them.

Multiples of 8 are 8, 16, **24**, 32, 40, **48**, 56, 64, **72**, 80, 88, **96**,...

Multiples of 12 are 12, **24**, 36, **48**, 60, **72**, 84, **96**, 108, 120, 132, 144,...

The least(lowest)Common multiples of 8 and 12 is 24.

### What are the common multiples of 3 and 4?

First, we find the multiples of 3 and 4 then we find common multiples between them.

Multiples of 3 are 3, 6, 9, **12**, 15,18, 21, **24**, 27, 30, 33, **36**,...

Multiples of 4 are 4, 8, **12**, 16, 20, **24**, 28, 32, **36**, 40, 44, 48,...

Common multiples of 3 and 4 are 12, 24, 36,...