Least Common Multiple  of 9 and 18 is 18

How to find the Least Common Multiple of 9 and 18?

On this page below, we'll use the Prime Factorisation, and the List of Multiples method to find out the LCM of 9 and 18.

Follow the steps below, and let's calculate the LCM of 9 and 18.


Method 1 - Prime factorization

Step 1: Create a list of all the prime factors of the numbers 9 and 18:

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 18

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

18 = 21x32


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

32, 21


Step 3: Multiply these values together:

32x21=18


Step 4: The result:

As seen on the calculation above, we have now obtained the LCM of 9 and 18.

The Least Common Multiple of 9 and 18 is 18.


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

Multiples of 18:

18, 36, 54, 72


Therefore,

LCM(9, 18) = 18