I've got some small puzzles for you all...
Use the four basic binary operations (+, -, *, /) and the four numbers 1, 5, 5, 5 to construct an expression that equals 24. (An example of such an expression is 1+5*5-5. This of course is equal to 21, but not 24.)
Another puzzle would be to construct an expression using the four numbers 0, 0, 0, 0 and any operations that you can think of. The expression must still be equal to 24.
Brackets are of course allowed if you need them in expressions such as 0*(0+0-0).
Answer: