Solving mathematical puzzles is a fun way to improve your problem solving skills. Inventing puzzles takes you even deeper into mathematical thinking, the same way writing a story takes you deeper into language and communicating than reading a story. Here are tips for creating your own Sudoku and Rush Hour puzzles.

HOW TO INVENT A SUDOKU PUZZLE

Twelve Sudoku puzzles

Answers to Sudoku puzzles

Blank grids for creating your own Sudoku Puzzles

1. **Start with a blank grid**. For ages 7 and under I suggest the 4x4 grid. For ages 8 and above I suggest the 5x5 or 6x6 grid.

2. **Fill in numbers** to make a complete solution. Then remove numbers, making sure there is just one solution. This is called working backwards. Or try working forwards: fill in numbers until there is a unique solution.

3. **Test your puzzle** on someone else. Is it solvable? Is it fun?

TAKING IT FURTHER

4. **Add a theme** by putting your puzzle into a story, or changing the numbers to pictures or letters. Or arrange the numbers to form a picture.

5. **Make a sequence** of puzzles that go from easy to hard. Like levels in a computer game, a sequence of puzzles lets players get into the game easily, then gradually learn how to solve harder challenges.

6. **Change the rules** if you want to make something more original. For instance, you can make a larger board, change the region shapes, or change the goal (for instance, require that the diagonals contain all the numbers).

HOW INVENT A RUSH HOUR PUZZLE

Blank grids for creating your own Rush Hour puzzles.

More information about Rush Hour and ThinkFun.

1. **Work backwards**. Put the escape car at the exit, put other pieces on the board, scramble.

2. **Or work forwards**. Put pieces on the board one at a time, making sure there is always a solution.