 ## How to find the Least Common Multiple of 9 and 20?

On this page below, we'll use the Prime Factorisation, and the List of Multiples method to find out the LCM of 9 and 20.

Follow the steps below, and let's calculate the LCM of 9 and 20.

### Method 1 - Prime factorization

#### Step 1: Create a list of all the prime factors of the numbers 9 and 20:

##### Prime factors of 9

The prime factors of 9 are 3 and 3. Prime factorization of 9 in exponential form is:

9 = 32

##### Prime factors of 20

The prime factors of 20 are 2, 2 and 5. Prime factorization of 20 in exponential form is:

20 = 22x51

32, 22, 51

32x22x51=180

#### Step 4: The result:

As seen on the calculation above, we have now obtained the LCM of 9 and 20.

The Least Common Multiple of 9 and 20 is 180.

### Method 2 - List of Multiples

Find and list multiples of each number until the first common multiple is found. This is the lowest common multiple.

#### Multiples of 9:

9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 117, 126, 135, 144, 153, 162, 171, 180, 189, 198, 207

#### Multiples of 20:

20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240

LCM(9, 20) = 180