Abstract: An apparatus includes a plurality of hand manipulative objects including containers with exteriors having substantially identical textures and colors. Each of the hand manipulative objects has a different weight equivalent to an integer multiple of a first weight. Contents of the containers substantially determine the weights. The weights include a consecutive series of weights including increments of one first weight. A user, manipulating the hand manipulative objects, can discern between different hand manipulative objects, thus enabling the user to convert feeling the weights into a representation of numbers and mathematical relationships.