# Revisiting the Abacus

October 21, 2009 —

When we were preparing for Wolfram|Alpha Homework Day, a tweet from @mwarntzen caught our attention: “just learned how to use an abacus while messing around on Wolfram|Alpha.” It brought smiles to our faces to think about this ancient tool being explored with our modern-day technology, and to think about how learning tools have evolved.

The abacus was developed as a counting tool long before the time of calculators. More modern versions of the abacus are wooden frames with rows of beads used for counting. Query “abacus” in the computation bar, and Wolfram|Alpha will return an abacus page (as shown below). You can enter a number, and Wolfram|Alpha will show you how the number would appear on a modern Chinese abacus.

Each column of beads represents a different place value: ones are in the rightmost column, tens in the next column to the left, and so forth. If none of the beads within a column are touching the center, that column represents zero. Moving a bead in the lower portion of the abacus toward the center adds 1 to that place value; moving the top bead down adds 5.

In this example we entered “374”: the rightmost column has the four bottom beads moved to the middle, the next one has two bottom beads and the top bead moved to the middle (2 + 5 = 7), and the next column to the left has three beads pushed to the center:

With all of today’s modern calculating tools, you may not find yourself in need of an abacus. But this is a fun interactive feature to explore.