I bought a starter set of Cuisenaire Rods a couple of weeks ago. They were used but in great condition. I pulled them out this week, and they're a real hit. I downloaded this free booklet of games and cards to use with the rods. (You'll need the cards to play some of the games.) We tried a couple of the activities today, and they really interested Superman. There are so many concepts that can be learned with this manipulative - addition, subtraction, measurement, fractions, spatial reasoning, and on and on with the possibilities! Can't wait to use these more over the summer.