Chapter 2: Addition, Subtraction, and Problem Solving
Written Addition, Subtraction and Problem Solving
Line up digits correctly, regroup with confidence, and decide which operation a word problem needs.
AI teacher
Press Start to hear a short classroom-style explanation. If sound is unavailable, the full script is shown below.
Voice: Browser voice
Workbook pages
Fun Maths Book 2 pages 10-31
Use column addition and subtraction, then solve multi-step word problems.
AI explanation
The AI teacher demonstrates vertical written methods with digits locked into place-value columns. It then models how to underline key information in word problems before choosing addition, subtraction or both.
- 1Line up ones under ones, tens under tens, hundreds under hundreds.
- 2When a column makes 10 or more, regroup into the next column.
- 3For subtraction, exchange from the next column only when the top digit is too small.
- 4For word problems, decide what changes first, then calculate carefully.
Think with the AI teacher
Today we are going to think like careful problem solvers. We will line up digits, regroup, and decide what the story is really asking.
Question 1
Pause 4sWhen we write 5083 - 276, where should the 6 go?
After thinking
The 6 goes in the ones column, under the 3.
Good eye. Place value keeps the calculation organised.
Question 2
Pause 4sIf a column makes more than 9 in addition, what should we do?
After thinking
We regroup into the next column.
Yes. Regrouping is just trading ten ones for one ten, or ten tens for one hundred.
Question 3
Pause 4sIn a word problem, should we calculate first or understand first?
After thinking
We understand first, then choose the operation.
Excellent. Mathematicians read before they calculate.
Deep structure
What children discover
Children see that column methods work because each column represents a different value, not because the digits are stacked randomly.
Common mistake
Children often misalign numbers with different lengths, especially when subtracting a 3-digit number from a 4-digit number.
Future connection
Strong written methods support multi-step IGCSE word problems, money problems, statistics totals and algebraic checking.
Animated demonstration
See the maths move
Digits drop into a vertical column grid, regrouping arrows appear, and a word-problem highlighter separates known numbers from the question.
Guided examples
Column addition
Find 4687 + 2756.
- 1.Ones: 7 + 6 = 13, write 3 and carry 1 ten.
- 2.Tens: 8 + 5 + 1 = 14, write 4 and carry 1 hundred.
- 3.Hundreds: 6 + 7 + 1 = 14, write 4 and carry 1 thousand.
- 4.Thousands: 4 + 2 + 1 = 7.
Two-step problem
A library has 3268 books. It buys 475 more and lends out 689. How many books are left?
- 1.First add the new books: 3268 + 475 = 3743.
- 2.Then subtract the books lent out: 3743 - 689.
- 3.Exchange carefully in the tens and hundreds columns.
Interactive practice
Try it now
Before solving each workbook word problem, underline the numbers and circle the action words.
In 5083 - 276, which columns must be lined up?
Find 729 + 486.
A shop had 950 stickers and sold 378. Which operation starts the solution?
Review
Show one addition and one subtraction column layout before opening pages 10-31.
Parent signal
If mistakes appear, check column alignment first before checking arithmetic facts.
Great careful thinking. Your neat layout is part of your maths.