Multiples of 18
Do you know that the multiples of 18 consist of the numbers that double the multiples of 9? Also, mathematically 18 is the only number where the sum of its written digits (1+8 = 9) is equal to half of itself (18/9 = 2). In this minilesson, we will calculate the multiples of 18, and interesting facts about these multiples.
 First five multiples of 18: 18, 36, 54, 72, 90
 Prime Factorization of 18: 18 = 2 × 3^{2}
1.  What are the Multiples of 18? 
2.  First 20 Multiples of 18 
3.  Important Notes 
4.  FAQs on Multiples of 18 
5.  Challenging Questions 
What are the Multiples of 18?
Multiples are the numbers that we get as a product of a number by an integer. a number × an integer = multiple.
The multiples of 18 are the number 18 multiplied by any integer. If n is an integer, then the nth multiple of 18 = 18 × n.
The first multiple of 18 = 18 × 1= 18
The 12th multiple of 18 = 18 × 12= 216
The 100th multiple of 18 = 18 × 100 = 1800
First 10 multiples of 18
Below you can see the first 10 multiples of 18:
List of First 20 Multiples of 18
Now we will find the first 20 multiples of 18 by multiplying 16 by each of the natural numbers from 1 to 20. Since multiplication is repeated addition, once we find the first multiple, we can add 18 to it to get another multiple and we can keep adding 18 to get the successive multiples.
Multiply 18 by the numbers from 1 to 20 
Multiples of 18 

18 × 1  18 
18 × 2  36 
18 × 3  54 
18 × 4  72 
18 × 5  90 
18 × 6  108 
18 × 7  126 
18 × 8  144 
18 × 9  162 
18 × 10  180 
18 × 11  198 
18 × 12  216 
18 × 13  234 
18 × 14  252 
18 ×15  270 
18 × 16  288 
18 × 17  306 
18 × 18  324 
18 × 19  342 
18 × 20  360 
To understand the concept of finding multiples, let us take a few more examples.
 Multiples of 20  The first five multiples of 20 are 20, 40, 60, 80, 100
 Multiples of 30  The first five multiples of 30 are 30, 60, 90, 120, 150
 Multiples of 18  The first five multiples of 18 are 18, 36, 54, 72, 90
 Multiples of 12  The first five multiples of 12 are 12, 24, 36, 48, 60
 Multiples of 36  The first five multiples of 36 are 36, 72, 108, 144, 180
Important Notes:
 Every number is a multiple of 1. i.e. 1 × 18=18 and 18 × 1= 18
 Multiples of 18 are infinite. There is no largest multiple of 18
 Multiples of 18 are >= 18
 All the multiples of 18 are multiples of 3
 All the multiples of 18 are multiples of 6
Challenging Questions:
 List all the multiples of 18 that are 2 digit numbers.
 Is 69, 642 a multiple of 18?
Multiples of 18 Solved Examples

Example 1: Richard plants 18 tulip plants in each row. How many plants will be there in all up to the 52nd row?
Solution:
In each row, he has 18 tulip plants.
In the 52nd row, he will have 18 plants.
So up to the nth row, he will have n × 18 plants
Up to the 52nd row, the total number of plants will be 52 × 18 = 936 plants
Therefore, 936 plants up to the 52nd row. 
Example 2: Jonathan is playing a video game. After every level, he gains a credit of 18 points. On completing the 18th level, how many points would he have scored?
Solution:
Credit gained at every level = 18 points
Credit gained at 18th level = 18 × 18 = 324 points
Therefore, Score at 18th level = 324 points.
Hence, 324 is the 18^{th} multiple of 18 
Example 3: Ron attends his gym classes every 18 days. If he has attended his first class today, in how many days will he attend his 6th class?
Solution:
If today is his first class, his next class will be after 18 days.
His 2nd class will be after 2 ×18 = 36 days
His 3rd class will be after 3 × 18 = 54 days
His nth class will be after n ×18 = 18 × n days
His 6th class will be after 6 × 18 = 108 days
Therefore, in 108 days he will attend his 6th class
FAQs on Multiples of 18
How do you find the multiples of 18?
Multiply any natural number with 18 and you will get the multiples of 18.
What is the 8th multiple of 18?
The 8th multiple of 18 is 144.
What are the first ten multiples of 18?
The first ten multiples of 18 are 18, 36, 54, 72, 90, 108, 126, 144, 162, 180.
What is the least common multiple of 18 and 8?
The least common multiple of 18 and 8 is 72.
Are the multiples of 18 always even?
Yes. We know that 18 is an even number and multiples of an even number are always even.
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