Let's think of this visually, as a pie. If you were to split a pie down the middle into two pieces and ate one slice, you would be eating half of it. Now, let's say you didn't eat one of those slices. You sliced the pie down the middle (vertically) and made another slice (horizontally). You would have 4 equal pieces. If you ate two slices that were side by side, you would still have had the same amount if you just sliced it once. If you were to keep slicing and eating, you'd be eating the same amount if you kept it to two pieces. Hope it helped!