This is the way we do it (or at least some of the ways).

1. This is the way we do it (or at least some of the ways). Calculation methods used in our school today. A guide for Parents and Carers.

2. “They didn’t do it like that in my day!” • Partitioning • Chunking • Number line • Grid multiplication

3. Which is more important? Mental Calculations Or Written Methods

4. When faced with a calculation, no matter how large or difficult the numbers may appear to be, all children should ask themselves: Can I do this in my head? If I can’t do it wholly in my head, what do I need to write down in order to help me calculate the answer? Do I know the approximate size of the answer? Will the written method I know be helpful?

5. On a whiteboard do this sum – 343 + 579 In your head work out £3.99 added to £4.56. Addition • How did you do it?

6. Adding – Informal Methods 86 + 57 +7 +50 +3 +4 86 136 140 143 143

7. Moving to a column method. 625 + 148 625 625 + 148 148 700 600 + 100 13 5 + 8 20 + 40 60 20 + 40 60 5 + 8 13 600 + 100 700 773 773

8. Using a Standard Method 7 + 5 = 12 Place the 2 in the units column and carry the 10 forward to the tens column. 587 + 475 587 + 475 80 + 70 = 150 then + 10 (carried forward) which totals 160. Place the 60 in the tens column and carry the 100 forward to the hundreds column. 1 0 6 2 1 1 500 + 400 = 900 then + 100 which totals 1000. Place this in the thousands column

9. On a whiteboard do this sum: 601 - 456 In your head work out how much change you get from £20.00 if you spend £14.75. Subtraction • How did you do it?

10. Subtraction – Taking Away How do the number line and the column method link? +4 +10 +300 +54 590 586 600 900 954 Find the difference between the two numbers. Count on from 586 to 954. 954 - 586 954 To make 590 Count onto the next multiple of 10 -586 4 To make 600 Count onto the next multiple of 100 10 Count on in 100’s 300 To make 900 54 Count onto the larger number 368 To make 954

11. On a whiteboard do this sum: 45 x 15 In your head work out how much you would spend if you bought 5 rolls of wallpaper at £16.99 Multiplication • How did you do it?

12. Multiplication Using a Number Line. 14 x 5 1 x 5 10 x 5 1 x 5 1 x 5 1 x 5 0 50 55 60 65 70

13. Grid Multiplication • Partitioning • Splits a number into its parts (makes it easy to see) • E.g. 14 x 5 = (10 x 5) + (4 x 5)

14. 14 x 5 (in a grid) 4 x 10 70 5 50 20

15. But can be done with “long multiplication”? 46 x 32 40 6 x 1380 30 1200 180 92 2 12 80 1472

16. 46 Expanded Method and Compact Method (you might recognise this one) 46 X 32 X 32 (40 x 30) 1200 1380 (46 x 30) (6 x 30) 180 92 (46 x 2) (40 x 2) 80 1472 (6 x 2) 12 1472

17. On a whiteboard do this sum: 640 divided by 12 In your head work out how many 20cm pieces of ribbon you can get from a 2.4m roll. Division • How did you do it?

18. Introducing division with a number line. 29 divided by 5 4 left over 10 15 20 25 29 0 5 5 groups of 5 with 4 left over 5 r 4 This can also be done backwards.

19. Chunking on a Number Line 72 divided by 5 0 2 22 72 R2 2 left! This is the remainder 5 x 4 Subtract 4 groups Of 5 from 22 to land on 2 5 x 10 Subtract 10 groups Of 5 from 72 to land on 22 14 r2 14 groups of 5 subtracted together

20. Turning this into a column 72 5 x 10 5 x 4 22 2 r2 72 div 5 = 14 r2 0

21. 256 divided by 7 Chunking 256 7 x 10 256 7 7 256 7 x 10 186 -70 7 x 30 7 x 10 -210 186 116 Subtract chunks of 70 (7 x 10) 7 x 10 46 -70 7 x 10 -42 7 x 6 116 46 7 x 10 4 -70 7 x 6 How many Groups of 7 in 46? 4 46 7 x 6 -42 r4 When comfortable with this then move onto compact method 0 4 36 r4 Total the numbers of groups of 7 10 + 10 + 10 + 6 = 36 r4