Alternatively, you can use a
knife to
slice it up.
Hold the mango so that the seed (stone) inside is horizontal, and now you can chop of everything above it, in one horizontal cut, and everything below the stone in one horizontal cut.
Now, you should have two pieces sliced away from the stone - now cut into these slices from the open end, almost to the skin, forming a grid pattern.
Now invert the sliced piece, and you can neatly bite off the little cubes - not only is this fun, but you can even use it to impress members of the opposite sex, small children, and probably any handy aliens as well.