Pie Graphs:  "like pieces of a pie"   A pie graph allows us to compare parts of a whole with each other, or the fraction of the whole each part takes up. That might sound a bit complicated, but it's easy when you think about it in terms of cake.  Let's say you eat half of the cake (you were hungry!) How much of the cake is left? Obviously, if you ate one side of the cake, then the other side is still there. But now say you weren't quite so hungry, so you only ate half of that half. How much is left of the cake now? You get the idea. The most you could ever possibly eat is the whole cake (100%), because after that, there's no more cake left! The less you eat of the cake, the more you have left over. Now consider two categories of trash collected from a beach : wood and plastic. Let's say that they were the only two types of trash found. If half the total trash we find is wood, then plastic must be the other half the trash found. But is it possible that half of the trash is wood IF more than half of it is plastic? NO WAY! That's the same thing as eating more than the whole cake! Once all the cake is gone, you can't eat any more!! (Are you still hungry??)   If you're hungry for still more on pie graphs check out the Beach Clean-Up example: Piece of Cake Back to Graph Types Overview