Like “magic”, Think-Its Math Mats take the drudgery out of learning math. Using an ordinary wipe-off marker, a child writes answers to questions and checks the answers by pressing a thumb over a concealed answer box. The child’s body heat dissolves embedded crystals and the correct answer is mysteriously revealed. These 2-sided mats are reusable so a child can practice addition, subtraction, multiplication and division at home, in class, or when traveling. Order No. 44029 - Addition Order No. 44039 - Subtraction Order No. 44049 - Multiplication Order No. 44059 - Division Order No. 44069 - Complete set of all 4