🧮 Soroban Basics

The Japanese abacus and how to represent numbers

The soroban is the Japanese abacus that helps you do fast mental math. It has several columns (rods) separated by a horizontal bar.

  • The bead above the bar is the heaven bead, worth 5.
  • The four beads below the bar are the earth beads, each worth 1.

A bead counts only when it is moved toward the bar. Each column is a place value: ones, tens, hundreds… from right to left.

Konsep utama

1 Value of a single column

Column value = (heaven bead if lowered ×5) + (number of raised earth beads). So the largest digit in one column is 9 = 5 + 4.

2 Representing numbers

To show 6, for example: lower the heaven bead (5) and raise one earth bead (1). Try the buttons below to see how numbers are formed.

Contoh interaktif

Pilih contoh, lalu tekan «Berikutnya» untuk melihat solusi langkah demi langkah di sempoa.