In many educational settings, manipulative materials (such as Cuisenaire Rods and Pattern Blocks) play an important role in children's learning, enabling children to explore mathematical and scientific concepts (such as number and shape) through direct manipulation of physical objects. Our group at de MJT Media Lab has developed a new generation of "digital manipulatives"-computationallyenhanced versions of traditional children's toys. These new manipulatives enable children to explore a new set of concepts (im particular, "systems concepts" such as feedback and emergence) that have previously been considered "too advanced" for children to learn. In this paper, we discuss four of our digital manipulatives-computationallyaugmented versions of blocks, beads, balls, and badges.