| 434 / | HD | EDUCATION AND DEMONSTRATION |
|
| 188 | DF | MATHEMATICS {4} |
| 191 |  | .~ Arithmetic {17} |
| 192 | DF | .~.~> Chalkboard or equivalent means having readily erasable surface |
| 193 | DF | .~.~> Manually manipulated numeral shaped elements |
| 194 | DF | .~.~> Numeric value represented by weight placed on balance |
| 195 | DF | .~.~> Manually manipulated elements having size proportional to numeric value {1} |
| 197 | DF | .~.~> Indicia-bearing belt or reel-mounted strip |
| 198 | DF | .~.~> Plaque (e.g., disk, etc.) turnable relative to index (e.g., window in card, etc.) to selectively align different points on plaque therewith |
| 199 | DF | .~.~> Plaque slidable relative to index (e.g., window in card, etc.) to selectively align different points on plaque therewith |
| 200 | DF | .~.~> Manually manipulated pin or peg |
| 201 | DF | .~.~> Electric component included in teaching means |
| 202 | DF | .~.~> Keyboard or like manually manipulated array (e.g., slides, levers, etc.) |
| 203 | DF | .~.~> Apertured elements threaded on elongate means (e.g., abacus, etc.) {1} |
| 205 | DF | .~.~> Means having number of marks (e.g., dots, etc.) or associated physical units (e.g., sticks, indentations, etc.) corresponding to numeric value |
| 206 | DF | .~.~> Rotatable wheel-shaped element (e.g., ring, disc, cylinder, etc.) having indicia on perimeter thereof |
| 207 | DF | .~.~> Color used in teaching means |
| 208 | DF | .~.~> Ball, block, or disk |
| 209 | DF | .~.~> Division or multiplication |
| 210 | DF | .~.~> Place value relative to decimal point |