The slide Fifteen puzzle or 15 puzzle is a very well known puzzle,include 15 wood squares numbered 1 to 15 are placed in a 5x5 try leaving one position open. The goal is to reposition the square from a given starting configuration to the configuration shown in the picture (all numbers in order).

This puzzle has a long history you can find many math theory on the web on solving it.

Dimensions: 12 x 12 x 2 cm

Difficulty: 2 out of 5