The manipulative blocks are used in all of the Math·U·See levels from Primer to Algebra 1. This is 133-piece manipulative block set of stacking blocks used to teach all aspects of arithmetic. The same blocks are used in conjunction with the Inserts to illustrate key algebra and decimal concepts. The box set consists of 20 ones and tens, 13 fives, and 10 each of twos, threes, fours, sixes, sevens, eights, nines, and hundreds blocks, plus the Decimal Street/Block Clock poster. The durable cardboard storage box doubles as a carrying case while keeping blocks tidy and simplifying clean up.