Multiplication — Class 2 IMO

Multiplication as Repeated Addition

Multiplication is a fast way to add equal groups. 3 groups of 4 = 4 + 4 + 4 = 12, which we write as 3 × 4 = 12. The sign × means times.

The order does not change the answer: 3 × 4 = 4 × 3 = 12.

Example 1: Write 5 + 5 + 5 as multiplication.

3 groups of 5 = 3 × 5 = 15.

Example 2: What is 2 × 6?

2 groups of 6 = 6 + 6 = 12.

Quick recap

Multiplication adds equal groups quickly.
× means times; 3 × 4 = 4 + 4 + 4 = 12.
Order does not matter: a × b = b × a.

✓ Quick check

4 + 4 + 4 = ___ × 4 ?

Three 4s means 3 × 4.

What is 2 × 7?

7 + 7 = 14.

Tables of 2, 5 and 10

The table of 2 counts in twos: 2, 4, 6, 8, 10… The table of 5 counts in fives: 5, 10, 15, 20… The table of 10 counts in tens: 10, 20, 30… Knowing these tables makes multiplication quick.

Example 1: What is 5 × 4?

Count by 5 four times: 5, 10, 15, 20. So 5 × 4 = 20.

Example 2: What is 10 × 3?

10, 20, 30. So 10 × 3 = 30.

Quick recap

Table of 2: 2, 4, 6, 8, 10…
Table of 5: 5, 10, 15, 20…
Table of 10: 10, 20, 30…

✓ Quick check

What is 5 × 6?

5, 10, 15, 20, 25, 30 — so 30.

What is 10 × 7?

10 × 7 = 70.

Equal Groups & Word Problems

Many real situations use equal groups: rows of chairs, packets of biscuits, wheels on cars. Find how many groups and how many in each group, then multiply.

Example 1: A car has 4 wheels. How many wheels on 3 cars?

3 × 4 = 12 wheels.

Example 2: 5 packets have 2 pens each. How many pens?

5 × 2 = 10 pens.

Quick recap

Look for equal groups in the problem.
Multiply groups × items in each group.

✓ Quick check

There are 6 boxes with 5 balls each. How many balls in all?

6 × 5 = 30 balls.

A hand has 5 fingers. How many fingers on 2 hands?

2 × 5 = 10 fingers.