National curriculum content
- Add and subtract whole numbers with more than 4 digits, including using formal written methods (columnar addition and subtraction)
- Add and subtract numbers mentally with increasingly large numbers
- Use rounding to check answers to calculations and determine, in the context of a problem, levels of accuracy
- Solve addition and subtraction multi-step problems in contexts, deciding which operations and methods to use and why
- Mental strategies
- Add whole numbers with more than four digits
- Subtract whole numbers with more than four digits
- Round to check answers
- Inverse operations (addition and subtraction)
- Multi-step addition and subtraction problems
- Compare calculations
- Find missing numbers
What we want children to know
- When to choose a mental strategy or a standard method
- How to use their place value knowledge to confidently exchange in addition and subtraction calculations
- How to check calculations using rounding and estimating
- That calculations can be checked for accuracy using inverse operations
- How to select the key information from a word problem and use a bar model to support finding a solution
What skills we want children to develop
Use knowledge to solve Reasoning and Problem Solving questions such as:
True or False?
3999 – 2999 = 4000 – 3000
3999 – 2999 = 3000 – 2000
2741 – 1263 = 2742 – 1264
2741 + 1263 = 2742 + 1264
2741 – 1263 = 2731 – 1253
2741 – 1263 = 2742 – 1252
Explain your reasoning.
Sam and Tom have £67·80 between them.
If Sam has £6·20 more than Tom, how much does Tom have?
1,235 people go on a school trip.
There are 1,179 children and 27 teachers. The rest are parents. How many parents are there?
Explain your method to a friend.
Always, sometimes, never
Is it always, sometimes or never true that the sum of four even numbers is divisible by 4?
- Why is it important to line the digits up correctly when we are adding numbers with different digits?
- Explain why we start in the lowest value place for addition and subtraction.
- In real life, when would we use an estimate?
- How can you tell if your answer is sensible?
- Which parts contain key information? Can we put them in a bar model to help solve the problem?