To stepwisely try a question enhanced in the degree of difficulty by providing a base on which inscription in partitions longitudinally and laterally divided into equal number is inscribed on the square bottom of a box, and providing the prescribed number of pieces into which a big square is divided into respectively different shapes.

The base on which the inspiration in the partitions longitudinally and laterally divided into the equal number is inscribed is provided on the bottom of the box 1 and the prescribed number of pieces 5 into which the big square is divided into respectively different shapes are housed in the box 1 to be enjoyed without remaining any pieces. Besides, the base on which the inscription is inscribed is provided and, even when the master frame of pieces 5 divided into the prescribed number of '10' is set at any inscription on the base, all the nine remaining pieces can be housed in the box 1 and played without remaining any piece. Concerning this building block puzzle tool, since a player can gradually and step-wisely try the high-level question from the very easy question, any child can spontaneously and positively tries it interestedly.