Subtraction calculation guidance

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Version 1 / June 2014

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Contents

Subtraction calculation guidance, Years 1 – 6

Year 1

Year 2

Year 3

Year 4

Stage 1

Stage 2

Year 5

Year 6

Stage 3

Stage 4

Stage 5

Stage 6

Stage 7

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

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YYeeaarr 11 ppuuppiillss sshhoouulldd bbee ttaauugghhtt ttoo::

• read, write and interpret mathematical statements involving …, subtraction (-) and equals (=) signs;

• represent and use number bonds and related subtraction facts within 20;

• … subtract one-digit and two-digit numbers to 20, including zero;

• solve one-step problems that involve … subtraction, using concrete objects and pictorial representations, and missing number problems such as 7 = - 9.

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• using concrete objects and pictorial representations, including those involving numbers, quantities and measures;

• applying their increasing knowledge of mental and written methods;

• recall and use … subtraction facts to 20 fluently, and derive and use related facts up to 100;

• … subtract numbers using concrete objects, pictorial representations, and mentally, including:

- a two-digit number and ones;

- a two-digit number and tens;

- two two-digit numbers;

- adding three one-digit numbers;

• show that addition of two numbers can be done in any order (commutative) and subtraction of one number from another cannot;

• recognise and use the inverse relationship between addition and subtraction and use this to check calculations and missing number problems.

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

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YYeeaarr 33 ppuuppiillss sshhoouulldd bbee ttaauugghhtt ttoo::

• … subtract numbers mentally, including:

- a three-digit number and ones;

- a three-digit number and tens;

- a three-digit number and hundreds;

• … subtract numbers with up to three digits, using formal written methods of columnar … subtraction;

• estimate the answer to a calculation and use inverse operations to check answers;

• solve problems, including missing number problems, using number facts, place value, and more complex addition and subtraction.

YYeeaarr 44 ppuuppiillss sshhoouulldd bbee ttaauugghhtt ttoo::

• … subtract numbers with up to 4 digits using the formal written methods of columnar … subtraction where appropriate;

• estimate and use inverse operations to check answers to a calculation;

• solve …subtraction two-step problems in contexts, deciding which operations and methods to use and why;

• solve simple measures and money problems involving…decimals to two decimal places.

YYeeaarr 55 ppuuppiillss sshhoouulldd bbee ttaauugghhtt ttoo::

• … subtract whole numbers with more than 4 digits, including using formal written methods (columnar subtraction);

• … subtract numbers mentally with increasingly large numbers;

• use rounding to check answers to calculations and determine, in the context of a problem, levels of accuracy;

• solve … subtraction multi-step problems in contexts, deciding which operations and methods to use and why;

• use all four operations to solve problems involving measure [for example, length, mass, volume, money] using decimal notation, including scaling.

YYeeaarr 66 ppuuppiillss sshhoouulldd bbee ttaauugghhtt ttoo::

• perform mental calculations, including with mixed operations and large numbers;

• use their knowledge of the order of operations to carry out calculations involving the four operations;

• solve … subtraction multi-step problems in contexts, deciding which operations and methods to use and why;

• solve problems involving addition, subtraction, multiplication and division;

• use estimation to check answers to calculations and determine, in the context of a problem, levels of accuracy;

• solve problems involving the calculation and conversion of unis of measure, using decimal notation up to three decimal places where appropriate.

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

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GEE 11

Relate subtraction to taking away from a group.

Count back using number tracks / number lines / 100 grids to support the development of the concept of subtraction as take away.

Develop subtraction facts initially to ten and then to 20.

Record related number facts (and make links to related addition facts), for example:

9 - 4 = 5

9 - 5 = 4

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GEE 22

Develop understanding of the equals sign / equality and the concept of ‘empty box’ questions.

Record solutions to calculations such as 9 - = 5.

Use understanding of patterning, place value and partitioning to derive number facts, for example:

7 - 3 = 4 (known fact)

17 - 3 = 14

27 - 3 = 24

Begin to use understanding of place value and partitioning to support subtraction of one-digit and two-digit numbers.

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

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GEE 33

Two-digit – one-digit.

Continue to develop understanding of partitioning and place value and use this to support subtraction.

41 - 8

41 - 1 - 7

41 - 8 = 33

Practical apparatus are used to support this, as are number tracks / 100 squares and number lines.

Record the outcomes of calculations in horizontal format.

41 - 8 = 33

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Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

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GEE 44

Pupils continue to continue to determine when calculations are best carried out using mental strategies.

Horizontal recording can begin to be replaced with recording in columns with a focus on place value. Use expanded recording and apparatus to illustrate concept initially if required before moving towards the formal written method.

No

Exchange: -

TT

4

U

8

7

  

-

40 + 8

7

40 + 1 = 41 becomes:

TT U

4 8

- 7

4 1

Exchange:

-

TT U

4 7

8

  

-

40 + 7

8

  

-

30 + 17

8

30 + 9 = 39

-

TT U

4 7

8

   becomes:

TT U

3 4 1 7

- 8

3 9

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

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GEE 55

Two-digit – two-digit .

Continue to determine when calculations are best carried out using mental strategies.

Develop use of the formal written method. Use expanded recording and apparatus to illustrate concept initially if required before moving towards the formal written method.

No exchange:

TT U

3 6

- 2 5

  

30 + 6

- 20 + 5

10 + 1 = 11 becomes:

TT U

3 6

- 2 5

1 1

Exchange:

TT U

4 5

- 2 6

  

-

40

20

+

+ becomes:

5

6

  

-

30

20

10

+

+

+

15

6

9 = 19

TT U

4 5

- 2 6

  

TT U

-

3 4

2

1

1 5

6

9

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

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STAGE 6

Three-digit – three-digit .

Continue to determine when calculations are best carried out using mental strategies.

Develop use of the formal written method. Use expanded recording and apparatus to illustrate concept initially if required before moving towards the formal written method.

Explore how the process relates to numbers with zeros as place holders.

No exchange, using an expanded method of recording if appropriate before moving to formal method:

300 + 30 + 6

- 200 + 20 + 5

H TT U

3 3 6

- 2 2 5

  

100 + 10 + 1 = 111

H TT U becomes:

3 3 6

- 2 2 5

1 1 1

H TT U

4 4 5

- 2 6 3

Exchange:

  

-

400 + 40 + 5

200 +

60 + 3

2

300 + 140 + 5

    

300 + 140 + 5

- 200 + 60 + 3

80 + 2

  

- 200 +

100 +

60

80

+

+

3

2 = 182

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

10

becomes:

-

H TT U

3 4 1

U

4 5

2 6 3

1 8 2

H TT U

4 0 5

- 2 6 9

Exchange with place holders

  

400 + 0 + 5

- 200 + 60 + 9

    

300 + 100 + 5

- 200 + 60 + 9

  

300 + 90 + 15

- 200 + 60 + 9

100 + 30 + 6 = 136

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

11

becomes:

-

3 4

2

1

9 1

TT

0

6

3

1 5

9

3

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

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GEE 77

Continue to determine when calculations are best carried out using mental strategies.

Develop use of the formal written method to subtraction of increasingly large numbers. Use expanded recording and apparatus as above to illustrate concept initially if required before moving towards the formal written method.

Introduce the use of the formal written method using decimal notation. Use informal and expanded recording, as well as apparatus as above, to illustrate concept initially as required before moving towards the formal written method. Develop within number range appropriate for the year group as outlined in the National Curriculum.

33.6 – 14.3

23.25 – 12.64

-

-

2

TT

3

1

1

TT

2

1

1

2

3

4

9

U

3 .

2

1

. 6

. 3

. 3

2 5

. 6 4

1 0 . 6 1

This material has been produced by Essex Education Services (EES) and may not be copied, duplicated or otherwise reproduced, for profit or otherwise, without the express permission in writing of EES .

Numicon ®, copyright © Oxford University Press 2010, reproduced with the kind permission of Oxford University Press.

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