| Abacus, plural abaci or abacuses, calculating device, probably of Babylonian origin, that was long important in commerce. |
| In Romanesque and Gothic work the capitals with their abaci take the place of the impost mouldings. |
| Liber abaci was not the first book written in Europe to describe the new numeral system. |
| The imported toys on show at the ongoing exhibition range from fighters, space-ships and battle-ships and building-blocks to abacuses. |
| The orchestra rattle abacuses for the sound of pattering tiles, but the dancers just prowl around tables. |
| Dr Jones believes they may have counted using the horizontal abacuses prevalent in other European nations. |
