Consolidation and practice
These resources are to support children in guided or independent work.
Opportunities to use and apply
Possible contexts include:
- Solving problems involving inverses, e.g. I think of a number, I subtract 9 and the answer is 20. What is my number? How did you work it out?
- Using inverses when calculating, e.g. what addition facts could you use to help you calculate these? 10 − 6, 20 − 8
- Checking, e.g. 14 +
= 25. What is the missing number? How do you know? What subtraction could you do to find the missing number?
- Reasoning, e.g. if you give me any addition number sentence I can write one more addition sentence and two subtraction sentences using the same numbers. Is it sometimes, always or never true?
- Word problems, e.g. eighteen children are on a bus. At the bus stop, five children get off and five children get on. How many children are on the bus now? How do you know?
Confirming learning
Ask probing questions such as:
- Catherine said that 32 − 27 = 6. Is she correct? Which addition calculation could she use to check her answer?
- Annie's teacher asked her to write two addition and two subtraction number sentences to link the numbers
3, 5 and 8.
She wrote these: 3 + 5 = 8, 5 + 3 = 8, 5 − 3 = 8, 3 − 5 = 8
Are they correct? Explain your thinking.
- Only one of these subtractions is correct. Which one is it? Explain how you know using the link between addition and subtraction.
30 − 7 = 25, 28 − 5 = 18, 25 − 6 = 19, 14 − 4 = 12
- Ling wants to check her answer to this subtraction:
73 − 45 = 28
Which of these tells Ling that her answer is correct?
A. 73 + 45 = 118, B. 45 + 28 = 73, C. 28 + 73 = 91
Calculating
Can I write addition and subtraction sentences that use the same three numbers and explain how they are linked? - teaching guidance | 45KB 
Addition and subtraction number sentences spreadsheet | 96KB