To get started with multiples, the easiest way is just to add a number to itself over and over again. For instance, if you want to find the multiples of 678 using this method, you could start at 678, and keep adding 678 over and over: 678, 1356, 2034, 2712, and so on. Each of these numbers is a multiple of 678. Usually, this method works with numbers that are easily added to itself. As you get into larger numbers, it can become difficult to continue adding.
Another way to do this, as discussed above, is to use choose any number and multiply it by 678. To find the first few multiples of 678, you could just multiply the 678 by 1, then 2, then 3, and so on, until you have as many multiples as you would like.
There are an endless number of multiples! You can keep using either of these methods to find as many multiples as you would like.