Q: by Zack
There is a large cube that is composed of small sugar cubes.
The large cube is 10 sugar cubes long, by 10 sugar cubes wide,
by 10 sugar cubes high. How many sugar cubes are on the surface of the large cube?

A: by Zack

This is not really a hard question (although I got it
wrong several times before I got it right due to
nervousness). However, there is the hard way to solve it
and the easy way to solve it.

Hard way:

Try to add up all the cubes on the surface.

So the top and bottom are each 10 x 10, which is 200. Two
more sides are 8 x 10 (since you don't count the two edges
already accounted for), which gives you 160. The last two
sides are 8 x 8 giving you 128.

So the answer is 200 + 160 + 128 = 488

Easy way:

The number of cubes on the outside/surface is simply the
total number of cubes minus the number of cubes on the
inside.