Consider that a piece of paper measured by its side lengths, (like 8 by 10), is actually telling you the area of the rectangle that is the paper, because area is . So to find how many can fit in a certain other piece of paper, you have to see how many times the area divides evenly. for your problem the smaller paper's area is and the larger area is: . So we need to see how many times 8 goes into 80, which turns out to be: , so you can fit 10 of the smaller peices of paper onto the larger piece. This method works of papers of any size, just find the areas and divide.