What is an abacus?
The abacus is one of the oldest calculating tools in the world. The version we use in this course is the Japanese soroban. It is simple, fast, and it trains children to see numbers in their mind, which is the foundation of abacus mental maths.
Parts of the soroban
- Frame – the outer border that holds everything together.
- Rods – the vertical wires. Each rod shows one digit.
- Beam – the horizontal bar that divides the beads. Beads only count when they touch the beam.
- Heaven bead – the single bead above the beam on each rod. It is worth 5.
- Earth beads – the four beads below the beam on each rod. Each one is worth 1.
Golden rule: a bead only counts when it is pushed towards the beam. Beads resting against the frame are worth zero.
Showing 0 to 9
To show a number on one rod, push earth beads up for ones and bring the heaven bead down for five.
Every number from 6 to 9 is 5 plus something: 6 is 5 + 1, 7 is 5 + 2, 8 is 5 + 3 and 9 is 5 + 4.
Holding the abacus
- Place the abacus flat on the table with the heaven beads at the top.
- Before every sum, clear it: tilt it towards you so all beads slide down, then run your index finger along the beam from left to right to push the heaven beads up.
- Use your thumb to push earth beads up and your index finger for everything else.
Try it yourself
Show the number 7 on the rod. Hint: 7 = 5 + 2.
Your abacus shows 0.
Quick check
Type your answers, then check them. Get them all right to complete the lesson automatically.
Practice tips
- Practise showing 0–9 in order, then in random order, until you can do it without looking at a chart.
- Say the number out loud as you move the beads. It builds the link between hand and mind.