your trying to solve what number can we subtract from 27,900 to get 22,500. A trick is to rewrite the question and line it up. Start by putting x into the space for the umber we are looking for.Looks like this:
27,900-x = 22500. Isolate the x value by subtracting 22,500 to 27,900 and adding x to the other side: 27,900-22,500 = x Line up the two number and you'll get your answer:
27,900
-22,500
5,400 = x
