Abstract: An educational device useful for teaching numbers, addition, subtraction, reading, and logic comprising a flat playing surface having rows of equally dimensioned boxes, ascending numerical indicia associated with the boxes in each horizontal row, blocks of varying dimensions having numbers thereon proportional to their relative horizontal dimensions and being adapted to fit in each row in such a way that the number appearing to the right of the block or block will indicate how may boxes are covered by the block or blocks in that row. In a preferred embodiment there is also provided a set of card containing a numbered card corresponding to each numbered block.