“PLUS” is a new puzzle with which you may build many shapes. Its originality lies in the main problem (see problem #25 page 11). Nothing was left to chance in the initial shape. Each piece has been logically designed in order to build the 5x4x2 rectangle parallelepiped. The pieces have been designed from two cobblestone-shaped pieces:
- one is sized 3x1x1
- the other one is sized 2x1x1.

Both pieces are assembled in every possible way and an extra piece in the shape of the “plus” sign is added. Thus we end up with nine pieces, as pictured page 2 of the original problems booklet. The shapes you are challenged to build are drawn on squared paper in order to show their size. Of course, these illustrations don’t give away the actual solutions. For example, one of the possible solutions to problem #1 is the initial shape of the puzzle.

The other shapes should be built using all the pieces, unless otherwise stated. The difficulty level is indicated for some more difficult problems (see range of difficulty page 15). A solution to the problems marked with an “S” is provided (see page 12). The other problems always have at least one solution. 

Thanks to the many possible combinations of pieces, you can also build your own shapes, as long as they contain forty-five unit cubes. Pages 13 & 14 are left blank for you to add your own designs.

We wish you much pleasure with the exciting “PLUS” puzzle!