A free abacus lesson plan for ages 11 to 14

By Kitson Workshop · 4 October 2026 · 5 minute read

In short: one 45-minute lesson, built around a free 5-minute video watched in four parts. Pupils trace sums in "dust", add with pebbles on a counting board, label a bead abacus, and finish by voting on a real 1946 contest between an abacus expert and an electric calculator. Everything below is yours to use. The printable version, with the worksheet, the exact pause times, a quiz and all the answers, is a free download.

What you need

• A way to play the free video to the group. Pupils don't need computers.
• A pencil and coloured pencils for each pupil
• About 20 dried beans or small counters for each pupil or pair
• Optional, for part 1: a tray with a thin layer of sand or salt

By the end, pupils can

• Say what an abacus is, and what it is not
• Show a number on a counting board with pebbles
• Match five big moments in the story to their dates

Key words

Think first (before the video)

Ask: "How would you add up a shopping bill if you had no paper, no pencil and no phone?" Take a few answers. Keep them on the board; you will come back to them.

The lesson, part by part

Play the video and pause at the end of each part. Each part has two questions to talk about in pairs, then something to try.

Part 1: Counting in clay

Pupils hear that nearly 4,000 years ago in Babylonia people pressed sums into wet clay, and that the first abacus was probably a board of sand or dust, used for writing before counting.

Talk: Why is dust a handy thing to do sums in? What is the problem with it?

Try: trace a sum with tally marks on a tray of sand or salt, or with a finger on the desk. Now wipe it clean: the very first reset button.

Part 2: Pebbles on a board

A counting board has lines, and pebbles on the lines stand for numbers. The Salamis Tablet, from about 300 BCE, is the oldest counting board we still have.

Talk: Why are pebbles better than marks in dust? What could go wrong with loose pebbles?

Try: on a counting board (lines for hundreds, tens and ones), show 243. Then add 125 by placing more pebbles. Answer: 368, with 3 on the hundreds line, 6 on the tens and 8 on the ones.

Part 3: Beads on rods

The Chinese suanpan, written about from around 1200, has beads on rods: two above the bar, five below. Nothing rolls away. By about 1600 the abacus had reached Japan and became the soroban; the modern one has one bead above and four below.

Talk: Which problem with pebbles do rods fix? Spot two differences between the suanpan and the soroban.

Try: label an abacus drawing: the frame, the bar, a rod and a bead.

Part 4: Abacus against machine

Tokyo, 1946: a soroban expert raced an electric calculator, and the soroban won four events out of five. The point the video makes: an abacus holds the numbers; the person does the thinking.

Talk: How could beads beat an electric machine? Is an abacus a computer? Say why, or why not.

Try: class vote, abacus or calculator. Everyone gives one reason before they vote.

Teaching notes: three things to be careful about

1. Counting boards are older than bead abacuses. Keep the order clear: dust, then pebbles on lines, then beads on rods.
2. "Probably" matters. The dust-board story is likely but not certain, and some historians doubt the link between the word abacus and dust. It is a good moment to ask: how do we know what happened so long ago? All early dates are approximate.
3. An abacus is not a computer. It stores numbers while a person calculates. A good answer to "is it a computer?" is no, because it cannot follow instructions by itself, but it shows the big idea that a number can be a thing you move.

About the 1946 score: there were five events (adding, subtracting, multiplying, dividing and a mixed problem). The soroban won four; the calculator won multiplication. The account comes from one book, Takashi Kojima's The Japanese Abacus, which quotes the army newspaper.

Extension

Find out how a soroban shows the number 7. Ask someone who learned it at school, or look it up, then teach the class.

Where it leads

This is Lesson 1 of 20 in our History of Computers series, which runs from the abacus to AI on your own desk at one lesson a week, about a term. Lesson 2 moves on to a shipwreck and the first calculating machines. See the whole unit at a glance.

For educational purposes only. Every drawing and every word in the lessons is our own.