This is a challenging math game for kids (and okay, adults) that requires no materials except a pencil and paper.

This is how we learned to play the game:

Write down the following numbers, either on a chalkboard or whiteboard or paper:

2, 3, 4, 5, 6, 7, 8, 9

Next, have the student (or yourself!) select four numbers—just circle them on the board.

2, 5, 7, 8

Now, the purpose of the game is find a way to use those four numbers–using addition, subtraction, multiplication, and/or division–to reach a result of 24.

And it works. No matter what four numbers you pick. It always, always works–somehow, someway, you can always reach the end result of 24. (Sometime this happens after much blood, sweat, and tears and insisting that nope, I happened to select the one combination of four integers that in fact will NOT result in 24 before one of your kids proves you wrong a minute or so later.)

It also never fails to torture me when I am unable to solve one of the combos.

Try playing this with your kids today! Select four numbers from 2, 3, 4, 5, 6, 7, 8, or 9 and use addition, subtraction, multiplication, and/or division to reach the result of 24.