Well, this one is kind of easy considering there are a lot of expressions that equal the same thing. Here are some examples of answers to 24;
12x2, 12+12, 6x4, 72/3, (6+6)x2
Or some harder ones;
6(1+3), 24-4+6-2
And that's all I can think of right now. But you get it I'm sure.
