Multiplying by 10, 100, 1000

Hello,

this week at school I've been Multiplying by 10, 100, 1000.
If you have any number that has a zero at the end of it like: 14 times 100. You'd do 14 times 1 and add the two zeros to get your answer.You can do this to any equation but, the bigger number you times the more zeros you will need to add to the end.This strategy is a simple way to times big numbers like this:
                                         (To view these images bigger click on them)

                 The way I solved this:                         
I can easily figure out this equation because, I know that 73 times 1 =73.
                    All you'd be left with is a zero.Add that to the end and that's your answer.