For a beginner, you can find the multiples of a number by skip-counting to the next number. For Instance, if you want to find the multiples of 1890, you could start at 1890, and keep adding 1890 over and over: 1890, 3780, 5670, 7560, and so on. Each of these numbers is a multiple of 1890. Typically, this works best only for smaller numbers, as adding larger numbers together over and over can be difficult.
Another way to do this is to use multiplication. To find the first few multiples of 1890, you could just multiply 1890 by each number in sequence, first multiplying by 1, then 2, then 3, and so on, which we will outline below.
