Linked from

The 20 pages that link to Abacus, each with the reason it gives.

• ArithmeticRelated: The abacus turns place-value arithmetic into physical bead movements.

• QuadriviumRelated: Abacus practice made the quadrivium’s arithmetic useful for routine computation.

• Tally marksRelated: Both an abacus and tallies externalize counting, but one uses movable counters and the other fixed marks.

• Yang HuiRelated: It illustrates the practical calculation culture behind Song-era arithmetic texts.

• Napier's bonesRelated: Like the bones, it externalizes place-value arithmetic in a hand-operated device.

• Qin JiushaoRelated: Calculation with counting rods provided the computational setting for his algorithms.

• Educational toyRelated: It supports calculation by making quantities and place value physically representable.

• Pope Sylvester IIRelated: Gerbert promoted a form of abacus calculation used in medieval teaching.