| 摘要 |
An arithmetical teaching aid includes a display board B comprising a rectangular array of display areas A arranged in rows R and columns C. Adjacent display areas A are marked (1, 10, 100 etc.) to represent successive powers of an arithmetic base number so that display areas A (where there are more than one) representing a given power of the base number (e.g. 1,000) are arranged diagonally across the board. Means (for example slides S) are provided for relatively moving the various rows R of display areas so that displays (e.g. 1,000) in the different rows R corresponding to the same power of the base number can be brought into columnar registration. All display areas A corresponding to a given power of the base number have a common tonal and/or textural characteristic which is different from the characteristic of each neighboring display area corresponding to a different power of the base number. Such characteristics are preferably provided by three different colors. The teaching aid further comprises sets of unit indicators (e.g. cubes) for display on the display areas A. Each unit indicator has a tonal and/or textural characteristic identifiable with that of a display area A on which it is to be placed.
|
