The first step to this method of finding the Least Common Multiple of 1 and 9 is to begin to list a few multiples for each number. If you need a refresher on how to find the multiples of these numbers, you can see the walkthroughs for those here:
Let’s take a look at the first 10 multiples for each of these numbers, 1 and 9:
First 10 Multiples of 1: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
First 10 Multiples of 9: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90
You can continue to list out the multiples of these numbers as long as needed to find a match. Once you do find a match, or several matches, the smallest of these matches would be the Least Common Multiple. For instance, the first matching multiple(s) of 1 and 9 are 9, 18, 27. Because 9 is the smallest, it is the least common multiple.
The LCM of 1 and 9 is 9.
