Low Ash Primary School – Calculations policy

1. Low Ash Primary School – Calculations policy Addition Strategies: Year 1 Counting on in 1s 7 + 6 = 13 4 5 6 7 0 1 2 3 8 9 10 11 12 13 14 Year 2 Counting on – partitioning into 10s and 1s + 10 + 2 23 + 12 = 35 23 33 35 Or 23 + 10 + 2 -> 23 + 10 = 33 then 33 + 2 = 35 Counting on – adding nearly numbers - add 9, 11 by adding 10 and adjusting by 1. + 10 35 + 9 = 44 -1 35 44 45 + 10 + 1 35 + 11 = 46 35 45 46 Year 3 As Year 2 but with larger numbers. Extend adding near multiples of 10 to a 2-digit number, e.g. 35 + 19. Pencil and paper procedures. 83 + 42 = 125 83 80 + 3 + 42 + 40 + 2 Or 5 120 + 5 = 125 120 125 Year 4/5/6 Continue with number line methods and 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 + 73 431 1 1

2. Low Ash Primary School – Calculations policy Subtraction Strategies: Year 1 Counting on/back in 1s 8 – 5 = 3 Find the difference by counting on. 4 5 6 7 0 1 2 3 8 9 10 9 – 2 = 7 Count back. 4 5 6 7 0 1 2 3 8 9 10 Year 2 Counting on – finding a difference + 1 + 2 42 – 39 = 3 39 40 42 Subtracting nearly numbers – subtract a multiple of 10 then adjust. - 10 35 – 9 = 26 +1 25 26 35 Counting back – partitioning into 10s and 1s. - 3 - 10 24 – 13 = 11 11 24 14 Year 3 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 4/5/6 Once a secure potential level 5 - introduce decomposition. Continue with number line methods for complementary addition, counting back and subtracting nearly numbers. Each year numbers should get larger and include decimals. 3 1 - 0.1 -0.3 6.1 – 0.4 = 5.7 546 5.7 6.1 6.0 Count back. - 318 228 +0.4 +0.8 6.8 – 5.6= 1.2 5.6 6.8 6.0 Count on.

3. Low Ash Primary School – Calculations policy Multiplication Strategies: Year 2 Arrays and repeated addition. 2 x 4 or 2 + 2 + 2 + 2 or 4 x 2 or 4 + 4 = 8 Or 0 1 2 3 4 5 6 7 8 Doubling – using partitioning. X 15 x 2 = 30 10 + 5 10 5 Or 2 20 10 X 2 = 30 20 + 10 = 30 Year 3 As Year 2 – use arrays and repeated addition and use known facts to carry out simple multiplications. X 32 x 3 = 96 30 2 3 = 96 90 6 Year 4/5/6 Continue with the grid method – each year numbers should get larger or include decimals. After Year 6 Sats introduce standard method. 2.4 x 3.9 = 9.36 172 x 38 =6536 57 X 9 X 20 4 X 30 70 100 2 600 120 63 x units 9 30 180 36 3000 2100 60 450 x tens 8 560 16 800 780 156 513 3800 2660 76 Treat as whole numbers, then readjust accordingly including a decimal point. 780 + 156 3800 2660 936 + 76 6536

4. Low Ash Primary School – Calculations policy Division Strategies: Year 2 Division as sharing and grouping. Grouping - There are 6 sweets. How many people can have 2 each? 1 2 3 6 – 2 = 3 : 0 2 4 6 Sharing – 6 sweets are shared between 2 people. How many do they each have? 6 – 2 = 3 : Year 3 As Year 2 – continue grouping and sharing – with larger numbers. Remainders. 1 2 3 4 5 16 – 3 = 5 r1 : 0 3 6 15 16 9 12 Year 4 As Year 3. Extend to harder numbers and begin to write out multiples. 10 x 4 10 x 4 4 x 4 96 – 4 = 24 : 0 40 80 96 10 x 4 10 x 4 4 x 4 24 x 4 1. X 4 = 4 2. X 4 = 8 3. X 4 = 12 4. X 4 = 16 5. X 4 = 20 6. X 4 = 24 7. X 4 = 28 8. X 4 = 32 9. X 4 = 36 10. X 4 = 40 (40) (80) (120) (160) (200) (240) (280) (320) (360) (400) 16 Year 5/6 0 3 2 As 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. 6 1 9 2 1 1 Include questions with remainder and decimal answers. Use the dot to represent a zero to make it a multiple of 10 Can reduce to 1, 2, 4, 5, 10 x