Abacus

By Xah Lee. Date: . Last updated: .

Abacus. Used in China and Japan, even today. There are 2 styles. Chinese and Japan style.

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Chinese abacus. abacus

Chinese style abacus has 2 rows at top, and 5 rows at bottow. This allows use with a hexadecimal numeral system (or any base up to 18).

The default position is away from the middle horizontal bar. Each bead positioned close to the horizontal bar counts a value. For bottom section beads, each bead counts as 1. For top section beads, each bead counts as 5.

Japanese Style Abacus

The Japanese style abacus has 1 row at top, 4 rows at bottom. For top section beads, each bead counts as 5. For bottom section beads, each bead counts as 1.

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Japan style abacus (soroban) with a reset button. (reset button pushes all beads away from the middle horizontal bar.) soroban

When i was in school aged around 9 (that's 1970s), abacus is still taught in school at Taiwan. And, there are TV shows of competition between students using abacus versus students using electronic calculator.

Amazing abacus addition by Japanese girl, age 7
real life use of Chinese abacus