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.
核心概念
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.
互动示例
选择一个示例，然后点击“下一步”在算盘上逐步查看解法。