Mathlink/Multilink cubes are a very versatile manipulative since they can be attached on all sides. These activity books make use of the unique properties of multilink cubes in varied exploratory activities. The Primary Book has activities to teach concepts of patterning and symmetry; counting and place value; addition and subtraction; multiplication and division; problem-solving and spatial reasoning; graphing and probability; estimating and measuring; and fractions. The Intermediate Book covers problem solving, fractions, probability, and algebra-readiness. The book uses a discovery approach, beginning with a question at the beginning of each exploration. First students think, then they "do", using the mathlink cubes to try to solve each of the 43 problems. I like the combination of practicing math skills with learning problem solving skills. Very well done.