A slide puzzle is a popular type of brainteaser involving a board with numerous moving blocks of equal length which need to be rearranged by the solver to form a picture or number sequence. Each board contains one empty space. However, the catch is that the pieces are only allowed to be rearranged by sliding one piece at a time into the empty space. Solving sliding block puzzles requires forward planning and strategic thinking.
Place your 24-inch-by-24-inch piece of cardboard on a flat surface and measure 2 inches in from each side. Mark the spot with a pencil. Draw straight lines connecting each side to form a 2-inch border inside the cardboard. The lines intersect near the corners of the cardboard, forming four small squares.
Cut out each of the four squares. Score each pencil line twice with the scissors. Fold the cardboard along the pencil lines and affix the corners together with glue or sellotape. This creates a 16-inch-by-16-inch open-top box.
Divide the 16-inch-by-16-inch card into 16 equal squares. Divide these squares using thin pencil lines. Score these lines with the scissors and then cut out 16 equal squares.
Label the squares 1 through 15 using the marker and place square 16 aside for another project. Arrange the squares in any order within the box. The solver rearranges the squares into numerical sequence by sliding them into the empty space.
Measure three times, mark twice, cut once. That's the best way to ensure that you get all the measurements right first time.
As this activity requires the use of markers, glue and scissors, do not allow young children to build this puzzle unsupervised.