Children will have hours of delight with this beautiful, heirloom-quality set of 100 large blocks, which come in a rainbow of colors and a multitude of lengths, all arranged in a wooden storage tray. Each solid wood piece has a constant thickness of 2 cm, with lengths varying from 2 to 10 cm (about 0.8 to 4 inches) long. The blocks can be arranged in or out of the frame as a stepped pyramid, or in an endless range of other designs and creative structures. This set offers stunning possibilities on its own, or integrates perfectly with any of Grimm"s small 2x2 building sets. Kids will have a great time stacking, arranging and building with these 100 modular cube forms. Just as importantly, in the process of play they"ll be introduced to such mathematical concepts as counting by multiples, proportion, sequencing, addition, subtraction, multiplication... even fractions. Learning has never been so much fun! Motivated by the principles of Waldorf and Montessori education, Grimm"s toys are designed to encourage children to engage in open-ended and independent play using simple yet vibrantly colored shapes. There are no instructions, and you can do no wrong with a Grimm"s toy. Just play, learn, and enjoy. Even adults can"t resist! Pieces are hand-cut and sanded, and lovingly finished with only non-toxic water-based stains that meet stringent US and European government safety standards. No lacquer is used in order to preserve the natural feel of the wood. Each wooden block is cut and sanded by hand, so there are no sharp edges or corners. The hand-applied water based stains are certified non-toxic, harmless to your health and suitable for children"s toys Note about Grimm"s colors: Because these blocks are not treated with lacquer, you may notice some color transfer one to another. However, because they are not lacquered, they preserve the natural feel of the wood, and are they are less likely to slip when stacking & building.