Our Earth is a really, really big ball - it's 8,000 miles wide. So how many cheeseburgers could we fit inside Earth if it were hollow? Balls work a lot like cubes: if a perfect cube is 2 times as wide as another, the bigger cube takes up 2 x 2 x 2 or *8* times as much space. Balls work the same way. We could count each burger as a 4-inch wide ball, and we know Earth is an 8,000-mile wide ball...let's find out how many we can smush in there!