Multiplication and Division
Primary 3 · Mathematics
Multiplication and Division
Lesson 3 of 3
13 min
On the way home, Mutesi, Byiringiro and Uwase pick 12 mangoes. They want to share them so that everybody gets the same. Nobody wants to be the one who ends up with fewer!
How many mangoes should each child take? This is a job for division.
Put the 12 mangoes in one pile. Now hand them out one at a time, going round and round the three friends.
Round 1: one mango each. That uses 3 mangoes. 9 are left.
Round 2: one mango each again. 3 more used. 6 are left.
Round 3: 3 more used. 3 are left.
Round 4: the last 3 go out. The pile is empty.
Each child received a mango on 4 rounds, so each child has 4 mangoes. Count them all back: 4 + 4 + 4 = 12. Nothing was lost, and the shares are equal.
We write this as 12 ÷ 3 = 4. The sign ÷ means shared into equal parts. Say it out loud: "twelve divided by three is four".
Now Uwase asks something else. She has 12 mangoes and small bags that hold 4 mangoes each. How many bags can she fill?
Fill the first bag: take away 4, and 8 are left. Fill the second bag: take away 4, and 4 are left. Fill the third bag: take away 4, and 0 are left.
She filled 3 bags, and we write 12 ÷ 4 = 3.
So division answers two kinds of question:
Look carefully at what just happened with the mangoes.
3 × 4 = 12. And 12 ÷ 3 = 4. And 12 ÷ 4 = 3.
The same three numbers — 3, 4 and 12 — keep coming back. Multiplication puts equal groups together. Division takes them apart again. They are opposites, like walking to school and walking home.
This is wonderful news: you do not need a new table for dividing. Your times tables already do the work.
What is 35 ÷ 5?
Step 1 Turn it into a times-table question. Ask yourself: 5 times what makes 35?
Step 2 Walk along the 5s, counting your steps: 5, 10, 15, 20, 25, 30, 35. You took seven steps.
Step 3 So 5 × 7 = 35, which means 35 ÷ 5 = 7.
Step 4. Check it. If 35 sweets are shared between 5 children, each gets 7 sweets, and 7 + 7 + 7 + 7 + 7 = 35. It works.
Try sharing 13 mangoes between 3 friends. Each child gets 4, and 1 mango is still sitting there.
That left-over amount has a name — a remainder — and you will meet remainders properly later on. In this lesson, every share comes out exactly even.
Tip
To divide, ask a times-table question
24 ÷ 4 is really asking "4 times what makes 24?" Walk up the 4s and count the steps: 4, 8, 12, 16, 20, 24 — six steps. So 24 ÷ 4 = 6.
Let your fingers count the steps for you. One finger for each jump.
For each one, ask the times-table question first. Then tap Show answer to check.
What you learned today
Quick check
15 mangoes are shared equally between 3 friends. How many does each friend get?
