| 摘要 |
A teaching aid (1) includes a frame (3) and an open-topped box (4), which are mounted on a base (2). The base (2) has wheels (7) for movement of the teaching aid (1). A support (6) is mounted adjacent an upper edge of the frame (2). The frame (2) has horizontally running rails (18). Two forms of blocks (21, 27) may be mounted on the rails. Both forms of blocks (21, 27) may have indicia on their faces. The blocks (27) are readily detachably mountable on the rails (18). The aid may also include indicia carrying stickers (31) which will removably adhere by electrostatic attraction to the blocks (21, 26). A transparent overlay (11) can be mounted on the support (6). |
