By Diana Braun Updated Aug 30, 2022
The abacus is one of the oldest computational tools, tracing its origins to ancient China. Traditionally, a Chinese abacus features a frame divided into an upper and lower section with 13 columns of beads. The upper part holds one or two beads each worth five units, while the lower part contains five beads each worth one unit. This simple yet powerful device can perform addition, subtraction, multiplication, and division.
Acquire an abacus and familiarize yourself with its layout. Remember that the upper beads represent five times the value of the lower beads. In each column, the rightmost column typically represents units, the next left column tens, the next hundreds, and so on.
Set the abacus upright so all beads rest at the bottom. Place it on a flat surface with the five‑bead section facing down.
Enter your first number by breaking it into individual digits. For example, to represent 36, move three beads up in the tens column (each bead equals 10). In the units column, move one bead up from the upper row (worth 5) and one bead up from the lower row (worth 1) to total 6.
To add a second number, repeat the digit‑by‑digit process and move additional beads up. For subtraction, reverse the motion: bring beads down from the ones already raised.
Count the beads in each column to determine the digit’s value. If a column exceeds nine beads, subtract ten and carry one bead to the next higher column. For instance, if the hundreds column reads 3, the tens 15, and units 2, reduce the tens to 5 and add one to the hundreds, yielding 451.
When working with large numbers, you can assign the rightmost column a higher base value—such as 10 or 100—to streamline calculations.
