How to make a "hide your secret" paper number trick

Check out this nifty game for the kids... watch this video to see how to make a "hide your secret" paper number trick. This is a paper trick that will let you hide your secret picture or number inside.

With a piece of A4 paper, fold in quarters one way and thirds the other, so you get a grid of 12 rectangles. That should start you off, now watch to see the rest of this paper trick.