Concept 6 of 7
Doubles & Halves
Today's big idea
Doubling adds a number to itself (× 2); halving splits it in two (÷ 2). They reverse each other.
Double 4 is 8, and half of 8 is back to 4.
How it works
👀 What's going on?
Fold a strip of stickers in half and the two halves match. Lay two matching strips end to end and you have double. Doubling and halving are opposites that undo each other.
💡 Here's the trick
Look at the counters above. Doubling means adding a number to itself, which is × 2. Halving means splitting a number into two equal parts, which is ÷ 2. Double 4 is 8; half of 8 is back to 4.
🪄 How to do it
- 1.Read whether you must double or halve.
- 2.To double, add the number to itself (× 2).
- 3.To halve, split the number into two equal parts (÷ 2).
✍️ Try it
- 1.What is double 4?
- 2.What is half of 8?
Double 4 is 4 + 4 = 8. Half of 8 splits into 4 and 4, so half of 8 is 4.
⚠️ Watch out
You can only halve evenly when the number is even. Half of 8 is a clean 4, but half of 7 would leave one left over — that is why we start with even numbers.
🌟 Why this matters
Doubling and halving help with money, sharing between two, and quick mental maths. They are the ×2 and ÷2 facts you will use most.
Exam tip: Double is add-itself; half is share-between-two. They reverse each other.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“What is half of 10?”
- 1
Halve means split in two
Two equal parts: 5 and 5.
- 2
That is ÷ 2
10 ÷ 2 = 5
- 3
Answer ✓
5
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
Doubling is ×2. Halving is ÷2 — sharing into two equal parts.
DOUBLE / HALF · ROUND 1 OF 3
Double 4
What is double 4?
Quick check
✅ VERIFICATION
What is half of 10?
⚡ Finish the activity above first to answer.
Keep going!
Up next: Find the Rule
2→10, 3→15, so the rule is × 5.