I'm trying to find fun puzzles for younger people (7 years of age and up). I've browsed the internet, searched through math books etc but haven't really found a stellar puzzle.
I realize that perhaps math does not lend itself to puzzles that well, since math is very logical, but maybe you can correct me.
Here are a few "puzzles" I have:
- I present a matrix of numbers (3x3). The solution is to sum each row and each column. And then to sum the summed rown and summed column. It's not very fun.
- I present a number, say 4, and two number properties (for example Even and Odd) and also "Neither" and "Both". This is challenging if it is on time.
- I present a matrix (5x5) of numbers. In this matrix there is a guaranteed sum of 100 "hiding". The total sum of all numbers are often above 1000 (it's not important). The goal is to strike out all numbers, leaving exactly 100. It's not brilliant but it's ok.
I have looked at hyper cubes, Magic Squares (far too difficult), textual problems etc. Sudoku is perhaps a superb example of a good math game (but also too hard for kids)
Maybe this question is unclear but I would love to hear anything you have to say or if you have any good book/link you can recommend.
Draw 3 houses and 3 utility companies. Try to connect every house to every utility without the pipes crossing. (Impossible because K3 is not planar, but there's lots of fun to be had trying).
The game of Nim. Lay out a handful of matches. Take turns to remove 1, 2, 3 or 4 matches. Try not to take the last match. (Winnning strategy is to leave $5n+1$ matches).
Make a stack of identical bricks. Now displace some of the bricks sideways. How far can you make the pile overhang? Only one brick allowed at each level. (Answer: as far as you like; $n$ bricks can overhang $O(\log n)$ distance).