magic house of numbers

I remember this book *well* from my elementary school days. I wore my brother's copy to pieces and had to buy a second one. Card tricks, games, puzzles (including instructions for building your own Chinese Ring Puzzle, whose quickest solution is the Gray-code sequence of binary numbers), all ways to impress your friends based on math. Unlike the Elkin Park reader, I would give this book to *every single child* in elementary school. I can't believe it's out of print... maybe the two of us should buy the rights.