noun
abacus
AB-uh-kuhs/ˈæbəkəs/
A frame with sliding beads used for counting and calculation.
Sliding beads fill the rods of the abacus.
Etymology
Greek abax named a counting or drawing board, originally covered with sand or dust for tracing and erasing calculations. The name later also denoted the bead-and-rod counting frame; the Greek word’s deeper origin is uncertain.
In context
we'll be identifying these beads as upper beads and lower beads on the abacus each column identifies a place value in our lessons we'll be using the rightmost column as the ones place
More examples
- She checked the sum using an abacus.
- An abacus stood beside the modern calculator.
- The lesson taught multiplication on an abacus.
Forms
abacus · abacuses · abaci
Similar words
- calculator
- A calculator usually computes electronically; an abacus uses movable counters.
- counting board
- A counting board may use loose counters on a surface; an abacus commonly holds beads on rods.