Lesson 6: Abacus Multiplication

Multiply a number by a single digit by adding partial products onto the abacus, left to right.

Intermediate 25 minutes Lesson 6 of 12

Before you start

Abacus multiplication needs the times tables up to 9 × 9. If any fact is slow, practise it first – the abacus will not help you with the facts themselves.

The method: partial products

Split the bigger number into its places, multiply each part by the single digit, and add each result on to the abacus.

Example: 23 × 4.

  1. Tens first: 20 × 4 = 80. Set 80 on the abacus.
  2. Ones next: 3 × 4 = 12. Add 12 to the abacus (1 on the tens rod, 2 on the ones rod).
  3. Read the answer: 92.
20 × 4 = 80
+ 3 × 4 = 12 → 92

Example: 146 × 3. 100 × 3 = 300, 40 × 3 = 120, 6 × 3 = 18. On the abacus: set 300, add 120 (→ 420), add 18 (→ 438).

Put each partial product on the right rod. 4 tens × 3 = 12 tens, so the 12 starts on the hundreds rod and ends on the tens rod.

Try it yourself

Work out 23 × 4 using partial products: set 80, then add 12.

Your abacus shows 0.

Quick check

Type your answers, then check them. Get them all right to complete the lesson automatically.

Practice tips

  • Always start with the highest place. Working left to right is faster on the abacus and matches how you read the answer.
  • Say each partial product out loud while you add it.