Review using column addition to add 2- and 3-digit numbers by regrouping tens | Maths

Starter quiz

What is the sum in this column addition?
- '79' ✓
In which column addition calculations do you need to regroup in the ones?
What is the sum in the column addition?
- '70' ✓
What is the sum in the column addition?
- '251' ✓
Which ones digit is missing from this column addition?
- '8' ✓
Which ones digit is missing from this column addition?
- '9' ✓

Exit quiz

In which column addition calculations do you need to regroup in the tens?
What is the sum in the column addition?
- '107' ✓
What is the sum in the column addition?
- '318' ✓
Which tens digit is missing from this column addition?
- '6' ✓
Which tens digit is missing from this column addition?
- '3' ✓
Match up the 2-digit numbers so that each pair has a sum of 125
- 73
  
  ⇔
  
  52 ✓
- 61
  
  ⇔
  
  64 ✓
- 83
  
  ⇔
  
  42 ✓
- 94
  
  ⇔
  
  31 ✓

Worksheet

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Presentation

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Lesson Details

Key learning points

When using column addition, start by adding the numbers with the smallest place value first.
If the sum of the tens digits is ten or greater, regrouping is needed.
Any complete hundreds are regrouped into the hundreds column.

Common misconception

Pupils may struggle to present regrouping in column addition.

Encourage pupils to talk about the process as they work through the problems. Model this in the lesson e.g. '5 tens add 7 tens is equal to 12 tens. 10 tens are regrouped as 1 hundred and written in the hundreds column.'

Keywords

Column addition - Column addition is a way of adding numbers by writing a number below another.
Regroup - The process of unitising and exchanging between place values is known as regrouping.