1. Keeping up with the Kids in Maths – KS1

2. Session 1 – What is Mastery? Subtraction

3. Aims of today To understand how we have changed the way we teach maths using the New National Curriculum To learn how this relates to teaching about subtraction Give you some ideas of how you can help your child at home

4. Maths is often abstract. We help the children to understand the abstract. This is reflected in our school calculation policies (you have one to take home).

5. Subtraction by taking away Starting with a real life situation puts it into context. Look at calculation policy 7 – 3 =

6. Taking away ones Starting with a real life situation puts it into context. Look at calculation policy

7. Taking away ones Starting with a real life situation puts it into context. Look at calculation policy

8. Taking away ones Starting with a real life situation puts it into context. Look at calculation policy

9. Taking away ones Starting with a real life situation puts it into context. Look at calculation policy 7 – 3 =4

10. Subtraction by counting back in ones Counting back needs to be linked to taking away initially – number track, bead string etc Look at calculation policy 9 – 2 =

11. Subtraction by counting back in ones Counting back needs to be linked to taking away initially Look at calculation policy 9 – 2 =

12. Subtraction by counting back in ones Counting back needs to be linked to taking away initially Look at calculation policy 9 – 2 =7

13. Subtraction by counting back in ones Can then count back on a number line Look at calculation policy 10 – 4 = 6

14. Subtract to Make 10 Look at calculation policy NB: This will help with mental strategies later- bridging through multiples of 10 Show how to calculate: 15 – 7 Using: Concrete – 10 frame and counters Pictorial – number lines

15. Subtraction using the Part-Part-Whole Model 6 4 6 4 Really useful to link addition and subtraction together https://www.ncetm.org.uk/resources/49419 Video clip 3

16. Subtract by finding the difference The word difference in maths doesn’t have the same meaning as in everyday life and this often confuses children. In maths, the difference is a method of subtraction where you compare two numbers. You find how many more or how many fewer one amount is compared to the other. It is a number.

17. Subtract by finding the difference Video clip 5 https://www.ncetm.org.uk/resources/49419

18. Linking finding the difference to the part-part-whole model 2

19. Notice the variation

20. Linking finding the difference to the part-part-whole model Notice the variation

21. Counting back in tens and ones 64 - 21 = Practice at home with your child counting forwards and backwards in tens and ones. 64 Without having to bridge ten

22. Counting back in tens and ones 64 - 21 = Practice at home with your child counting forwards and backwards in tens and ones. 54 Without having to bridge ten

23. Counting back in tens and ones 64 - 21 = Practice at home with your child counting forwards and backwards in tens and ones. 44 Without having to bridge ten

24. Counting back in tens and ones 64 - 21 = Practice at home with your child counting forwards and backwards in tens and ones. Without having to bridge ten 43

25. Counting back in tens and ones Then on a number line this time bridging ten How is this different to the last method? Have a go 43 – 24 Look at the calculation policy to help you.

26. As before but instead of counting back- partition both numbers and take away the correct number of units and tens. Then count how many left. 46 – 14 = 40 6 10 4 40 – 10 = 6 – 4 = Subtracting two 2-digit numbers by partitioning and taking away

27. As before but instead of counting back- partition both numbers and take away the correct number of units and tens. Then count how many left. 46 – 14 = 32 40 6 10 4 40 – 10 = 30 6 – 4 = 2 30 + 2 = 32 Subtracting two 2-digit numbers by partitioning and taking away

28. Reasoning and Problem Solving Looking at the calculation policy - which is the best way for a Y2 pupil to work out 74 – 56? Explain why to the person next to you.

29. Reasoning and Problem Solving

30. How to help at home Practise counting in ones, tens, twos, fives, threes (backwards and forwards) Practise number facts e.g. number bonds, times tables Remember, if your child is finding something in maths difficult to understand use C – P – A Buy some drinking straws to make bundles of ten and use to help them understand Collect 10p coins and 1p coins and use them to help them understand Draw pictures or ideas from the calculation policy to help them understand

31. Thank you -Any questions? Next week multiplication, division and fractions