Ages

Introduction

Summary

This animation represents the Japanese abacus (soroban). Balls are strung along rods (columns). Each rod corresponds, going from right to left, to ones, tens, hundreds, thousands…

The upper balls have a value of 5. The lower ones have a value of 1. In other words, an upper ball on the third rod from the right has a value of 5 hundreds (500).

A lower ball on the second rod from the right has a value of ten (10).

A ball is only counted when it has been moved  down to the transverse (horizontal) bar.

The principle of the abacus has been known since the 3^rd millenium BCE (the Mesopotamians). It enables one to carry out simple operations like additions and subtractions, but, in expert hands, the abacus can also be used to carry out multiplications, divisions, and even the calculation of roots.

The soroban is a descendant of the Chinese abacus (suanpan), but it has one less ball on both the upper and lower levels. The soroban is still in widespread use among the Japanese. It can be found in all of their schools, because it is very visual tool for illustrating the principles of the base ten (decimal) numeral  system.  Moreover, one frequently sees merchants verifying their calculations with a soroban,  placed just beneath the cash register.

On November 12,  1946, a competition was held  that set a soroban expert in opposition to someone using one of the first electronic calculators.  The soroban won, 4 trials to 1.

It is very impressive to watch the Japanese perform anzan (blind calculation). With a lot of training, a soroban expert can obtain a mental picture of his tool and perform complex calculations by running his fingers over an imaginary soroban.

Goals

• To illustrate the principles of the base ten system.
• To illustrate the rule of complements of 5 and 10.
• To visualize carrying over.

Features

Click on a ball in order to slide it.

Click on the "labels" button (three horizontal lines inside a circle) on the navigation bar to show or hide the values.

Tags

calculator Addition Multiplication Japan abacus