The challenge of these puzzles is in working backwards. Given the median, range, mean, or mode for each column and row of a grid, the challenge is to fill in all the numbers and complete the grid. Here’s an example:

These puzzles were created by a math teacher named Mark Chubb. For more from Mark, check out his piece A Few Simple Beliefs – where he writes about what it could look like in a class room where conceptual understanding of average comes before the procedures.