Multiplying a number by 1,000 moves each digit 3 places to the left. This is because 1,000 has three zeros. For example, if you start with the number 35 and multiply it by 1,000, you can think of it as adding three zeros to the right:
35 x 1,000 = 35,000
So, in effect, each digit shifts three places to the left in the decimal representation.