Perfectly Designed and Creatively Inspiring Ideal Fractional Tablets Set, Complete

I'm always excited to find beautifully designed old creative learning materials, and am especially enamored with this set of "Fraction Learning Tablets" produced by the Ideal School Supply Co. of Chicago, another set of which I've never seen. Not designed by Frederick Froebel, but completely aligned with his blocks sets--here with paper "tablets" divided into halves, thirds, quarters, etc., and purple cardboard shapes of corresponding, sequentially divided proportions, used to cultivate understanding of fractions, i.e. parts adding up to wholes. Excellent for young learners now, equally great from a design and standpoint, and mighty satisfying just to play around with, constructing patterns and compositions.

Box 4 5/16 x 6 5/16 x 1 1/8. "Tablets": 3 7/8” x 3 7/8”. Complete (amazing!) and in very good condition, just a few small toning stains, no matter. First decade 20th c. I believe.