Low Ash Primary School – Calculations policy Addition Strategies:

7 + 6 = 13 4 5 6 70 1 2 3 8 9 1110 1312 14

Counting on in 1s

Counting on – partitioning into 10s and 1s

23 + 12 = 3523 33 35

+ 10 + 2

Or 23 + 10 + 2 -> 23 + 10 = 33 then 33 + 2 = 35

Year 1

Year 2

Counting on – adding nearly numbers - add 9, 11 by adding 10 and adjusting by 1.

35 44 45

+ 1035 + 9 = 44 -1

As Year 2 but with larger numbers. Extend adding near multiples of 10 to a 2-digit number, e.g. 35 + 19.

Year 3

Pencil and paper procedures.

83 + 42 = 125 83+ 42

120 5

125

Or

80 + 3+ 40 + 2120 + 5 = 125

Year 4/5/6Continue with number line methodsand pencil and paper procedures. Extend adding nearly numbers e.g. 125 + 59, 165 + 81, 143 + 4.9, 234 + 5.1

Refine column addition - including larger and decimal numbers.

358+ 73

4311 1

35 45 46+ 1035 + 11 = 46 + 1

Low Ash Primary School – Calculations policy Subtraction Strategies:

Counting on/back in 1sYear 1

9 – 2 = 7

8 – 5 = 34 5 6 70 1 2 3 8 9 10

4 5 6 70 1 2 3 8 9 10Counting on – finding a difference

42 – 39 = 339 40 42

+ 1 + 2

Year 2

Subtracting nearly numbers – subtract a multiple of 10 then adjust.

25 26 35

- 1035 – 9 = 26 +1

Counting back – partitioning into 10s and 1s.

24 – 13 = 1111 14 24

- 3 - 10

As Year 2 but with larger numbers. Extend subtracting near multiples of 10 to a 2-digit number, e.g. 35 - 19. Develop complementary addition (counting on).

Year 3

Year 4/5/6Continue with number line methods for complementary addition, counting back and subtracting nearly numbers. Each year numbers should get larger and include decimals.

Once a secure potential level 5 - introduce decomposition.

546- 318

3 1

5.7 6.0 6.1-0.3 - 0.16.1 – 0.4 = 5.7

228

5.6 6.0 6.8+0.4 +0.86.8 – 5.6= 1.2

Find the difference by counting on.

Count back.

Count back.

Count on.

Low Ash Primary School – Calculations policy Multiplication Strategies:

2 x 4 or 2 + 2 + 2 + 2 or 4 x 2 or 4 + 4 = 8Arrays and repeated addition.Year 2

2 30 1 4 5 76 8Doubling – using partitioning.15 x 2 = 30 10 + 5

X 2

20 + 10 = 30

Or X 10 52 1020

= 30Year 3As Year 2 – use arrays and repeated addition and use known facts to carry out simple multiplications.

32 x 3 = 96 X 30 23 690 = 96

Year 4/5/6Continue with the grid method – each year numbers should get larger or include decimals.

172 x 38 =6536

X 70 230 602100 8 560 16

6536

After Year 6 Sats introduce standard method.

57 X 9

63 x units

450 x tens

513

Or

100

3000

800 3800 2660 76

38002660

+ 76

2.4 x 3.9 = 9.36

X 20 430 120600

9 180 36

780 156

780 + 156

936

Treat as whole numbers, then readjust accordingly including a decimal point.

Low Ash Primary School – Calculations policy Division Strategies:

Grouping - There are 6 sweets. How many people can have 2 each?

20 4 6

Division as sharing and grouping.

Sharing – 6 sweets are shared between 2 people. How many do they each have?

Year 2

Year 3As Year 2 – continue grouping and sharing – with larger numbers.

Remainders.

30 6 916 – 3 = 5 r1:

12 15 16Year 4As Year 3. Extend to harder numbers and begin to write out multiples.

1. X 4 = 4 2. X 4 = 83. X 4 = 124. X 4 = 165. X 4 = 206. X 4 = 247. X 4 = 288. X 4 = 329. X 4 = 3610. X 4 = 40

(40)(80)(120)(160)(200)(240)(280)(320)(360)(400)

Use the dot to represent a zero to make it a multiple of 10

96 – 4 = 24: 400 80 96

10 x 4 10 x 4 4 x 4

1610 x 4 10 x 44 x 4

24 x 4

Year 5/6As Year 4. Extend to larger numbers. Year 5 summer term onwards – children secure with number line and secure potential level 5’s can move on to short division.

1 9 260 3 2

1 1

Include questions with remainder and decimal answers.Can reduce to 1, 2, 4, 5, 10 x

1 2 3

1 2 3 4 5

6 – 2 = 3:

6 – 2 = 3: