| 摘要 |
<p>The apparatus comprises a horizontal board (3), which is divided into eleven zones (4), and a vertical board (1), which is divided into eleven vertically-extending zones (8) and two horizontally-extending zones (9) and has two outwardly-projecting subsidiary boards (2). In use, objects (see Figure 5) can be placed in selected zones (4) of the horizontal board (3) to demonstrate a mathematical operation (for example addition or subtraction) and information relating to the operation is written on appropriate zones (8) of the vertical board (1) and on the subsidiary boards (2). The horizontal board (3) has a bevelied front edge portion (6), on which further information can be written, and two portions (5) in which objects to be placed in the zones (4) of the horizontal board (3) can be placed beforehand.</p> |
