Add with the columns lined up
23 + 14 works because the tens and ones are in the correct places.
Add the ones first: 3 + 4 = 7. Then add the tens: 2 tens + 1 ten = 3 tens. So the answer is 37.
Year 2
Use the column method for addition and subtraction without carrying or borrowing
Line up tens and ones in columns so simple addition and subtraction can be read clearly without carrying or borrowing.
Lesson overview
Number - addition and subtraction
The column method helps us keep tens under tens and ones under ones. When the numbers are lined up carefully, we can work one column at a time. In this first step, we only use examples where no carrying or borrowing is needed.
Subtract with the columns lined up
46 - 12 can be worked out one column at a time.
Subtract the ones: 6 - 2 = 4. Then subtract the tens: 4 tens - 1 ten = 3 tens. So the answer is 34.
The columns must stay in place-value order
34 + 20 means only the tens change.
The 2 tens must sit under the tens column. That keeps the ones at 4 and gives an answer of 54.
Worked example
Work out 52 - 21 using columns.
- Write the numbers in columns with tens under tens and ones under ones.
- Start with the ones column.
- 2 - 1 = 1, so write 1 in the ones place.
- Now look at the tens column.
- 5 tens - 2 tens = 3 tens.
- So 52 - 21 = 31.
Try it
Look at the columns carefully, then choose the correct answer.
Question 1
Question 2
Question 3
Question 4
Question 5
Common mistakes
These are the slips to watch for when using columns for the first time.
- Putting a tens digit in the ones column.
- Reading across instead of working by place-value columns.
- Trying examples that need carrying or borrowing before the method is secure.
Related topics
These ideas support place-value alignment and careful written calculation.
- Add tens and ones using unit cubes and tens rods.
- Add and subtract numbers using concrete objects and pictorial representations, including two two-digit numbers.
- Recognise and use the inverse relationship between addition and subtraction and use this to check calculations and solve missing number problems.