## How to find the Least Common Multiple of 5 and 18?

On this page below, we'll use the Prime Factorisation, and the List of Multiples method to find out the LCM of 5 and 18.

Follow the steps below, and let's calculate the LCM of 5 and 18.

### Method 1 - Prime factorization

#### Step 1: Create a list of all the prime factors of the numbers 5 and 18:

##### Prime factors of 5

The prime factors of **5** are **5**.
Prime factorization of **5** in exponential form is:

**5** = 5^{1}

##### Prime factors of 18

The prime factors of **18** are **2, 3 and 3**.
Prime factorization of **18** in exponential form is:

**18** = 2^{1}x3^{2}

#### Step 2: Identify the highest power of each prime number from the above boxes:

5^{1}, 2^{1}, 3^{2}

#### Step 3: Multiply these values together:

5^{1}x2^{1}x3^{2}=**90**

#### Step 4: The result:

As seen on the calculation above, we have now obtained the LCM of 5 and 18.

The Least Common Multiple of **5 and 18** is **90**.

### 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 **5**:

5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105

#### Multiples of **18**:

18, 36, 54, 72, 90, 108, 126, 144

#### Therefore,

LCM(5, 18) = **90**