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Calculations Guidance on pencil and paper methods Dale Community Primary School

Dale Calculations Policy

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Calculations policy for the school 2012/13.

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Page 1: Dale Calculations Policy

CalculationsGuidance

on pencil and paper methods

Dale Community Primary School

Page 2: Dale Calculations Policy

Steps to SuccessInformation for ParentsThe long-term aim is for children to be ableto select an efficient method of their choice (whether this be mental, written or in upper Key Stage 2, using a calculator) that is appropriate for a given task.

They should always be asking themselves:

What is a rough answer (estimate) to this question?Shall I do this in my head?Shall I do this in my head using drawings or jottings?Should I use a pencil and paper procedure?Shall I use a calculator?

Those Very First Steps in CalculationsChildren, at an early age, should be encouraged through, practical experiences, to:Show an interest in number problems.

Separate a group of three or four objects in different ways, beginning to recognise that the total is still the same.

Compare two groups of objects, saying when they have the same number.

Count repeated groups of the same size.Share objects into equal groups and count how many in each group.

Find one more or one less than a number from one to ten.

Use the vocabulary involved in adding and subtracting.

Say the number that is one more than a given number.

Select two groups of objects to make a given total of objects.

Use language such as ‘more’ or ‘less’ to compare two numbers.

Begin to relate addition to combining two groups of objects and subtraction to ‘taking away’.

Use own methods to work through a problem.Find the total number of items in two groups by counting all of them.

NUMICON SHOULD BE USED AT ALL AVAILABLE OPPORTUNITIES TO SUPPORT CHILDREN’S UNDERSTANDING OF CALCULATIONS. IT SHOULD BE AN INTEGRAL PART OF EARLY CALCULATION AT DALE.

Page 3: Dale Calculations Policy

Steps to SuccessHigher Steps of CalculationWhen children reach the higher steps of calculation

(step 5 and above) they should be estimating the answer before calculating. They record these estimates in a bubble:

“28 children are given 4 sweets each, how many are there altogether?”

T U

x 20 8

4 80 32

8 0

+ 3 2

1 1 2

30x4=120

Page 4: Dale Calculations Policy

Progression through Calculations

LanguageAdd together; plus; add; sum

Mental recall of number bonds6 + 4 = 10 + 3 = 1025 + 75 = 100 19 + = 20

Use near doubles6 + 7 = double 6 add 1 = 13

Addition using partitioningand recombining34 + 45 = (30 + 40) + (4 + 5) = 79

Counting on or back inrepeated steps 1, 10, 100, 100086 + 57 = 143(by counting on in tens and then in ones)

460 + 300 = 760(by counting on in hundreds)

Add the nearest multiple of10, 100, and 1000 and adjust24 + 19 = 24 + 20 – 1 = 43458 + 71 = 458 + 70 + 1 = 529

Use the relationship betweenaddition and subtraction36 + 19 = 55 19 + 36 = 5555 – 19 = 36 55 – 36 = 19

Addition

Page 5: Dale Calculations Policy

Progression through Calculations

SubtractionLanguageTake away; subtract; minus;find the difference

Mental recall of number bonds10 – 6 = 4 17 - = 1120 – 17 = 3 10 - = 2

Find a small difference by counting up82 – 79 = 3

Counting on or back inrepeated steps 1, 10, 100, 100086 - 52 = 34(by counting back in tens and then in ones)

460 – 300 = 160(by counting back in hundreds)

Subtract the nearest multiple of10, 100, and 1000 and adjust24 - 19 = 24 – 20 + 1 = 5458 – 71 = 458 – 70 – 1 = 387

Use the relationship betweenaddition and subtraction36 + 19 = 55 19 + 36 = 5555 – 19 = 36 55 – 36 = 19

Page 6: Dale Calculations Policy

Addition

Step 2:Children are encouraged to develop a mental picture in their heads of the number system.Children develop ways of recording calculations using a pictorial format.“If I add 2 ice lollies to 3 ice lollies how many have I got altogether?”

2 3 4 5+

Step 1:Children will start by counting each and every object to arrive at the total. “Peter has 3 balloons and Jasdeep has 2, how many balloons are there altogether?”

Children will need to know the correct sequence of numbers.

Page 7: Dale Calculations Policy

Step 4:Children develop skills by taking the first whole number and adding the individual tens of the second and then adding on individual units.

“Hamzah wants to find the sum of 27 pence and 34 pence, how much has he altogether?”

+10 +10 +1+1+1+1+1+1+1

34 44 54 610

27

AdditionStep 3:Children develop addition skills by using number lines to count on in ones.“What is the total of 4 sweets added to 8 sweets?”

A child would use the number line to say “8” and then add on the four “1,2,3,4” giving total of 12.

Children should be encouraged to put the greater number first.

0 1 2 3 4 5 6 7 8 9 10 11 12 13 1514

+1+1+1+1

Page 8: Dale Calculations Policy

Addition

Step 6:Children develop partitioning of the problem by the tens and then the units. “Ben adds 42 seeds to a jar already containing 35 sunflower seeds, he wants to know how many he has altogether?”

42 = 40 + 2 and 35 = 30 + 5

0 40 70 75

+40 +30 +5+2

77

Step 5:Children now need to develop partitioning the addition into larger groups of tens and units.“Jessica spends 36 pence on sweets and Gaganpreet spends 28 pence. How much have they spent altogether?”

+20

36 56 640

28+8

Page 9: Dale Calculations Policy

Step 8:Children now progress to addition using columns. Adding the units/ones column first then tens column.Ingrid adds 56 stars to 83 squares.“How many shapes altogether?”

5683

TU

99 units (6+3)130 tens (50+80)

139

AdditionStep 7:Children now move onto the more formal way of recording, but need to be very secure on the previous stages before trying to record in this manner.“Shamsa adds 67 buttons to Justyna’s 45. How many altogether?”

60 + 740 + 5

100 + 12 = 112

Page 10: Dale Calculations Policy

AdditionStep 9:Children have now reached a formal method showing numbers carried underneath the correct column. “Katie scores 165 points in her first game which she adds to her second score of 58. How many points did she score altogether?”

H T U1 6 5

5 82 2 31 1

Page 11: Dale Calculations Policy

AdditionStep 10:Children need a good knowledge of place value to make sure numbers are in the correct column. They now extend to numbers with any number of digits and various decimal places.“Qasim measures 3 distances, 53.42m; 362.8m and 2.984m. What is the total distance measured?”

3 6 22

8

4 1 9

5 3 4 2

89 440

1

221

+

Page 12: Dale Calculations Policy

Subtraction

Step 2:Children slowly move from the concrete apparatus to using a number line as well. “Menaz has 14 pence she buys a bag of sweets for 6 pence, how much has she got left?”

Using number lines to count back in ones.

-6 -5 -4 -3 -2 -1

0 1 2 3 4 5 6 7 8 9 10 11 12 13 1514

Step 1:As with addition, children learn to use objects, and remove “ones” from a group. “James has 7 marbles, Asad takes away 3, how many marbles has James now got?”

-1 -1 -1

7 Marbles take away leaves 4-1 -1 -1

Page 13: Dale Calculations Policy

Subtraction

Step 4:Children find a small differenceby counting up. “James has a money box containing 53 pence he takes away 47 pence, how much has he got left?”

+3

47 50 53

+3

Step 3:Counting on, using a number line, to find the difference between numbers (known as the shopkeeper’s method).Mandla asks, “What is the differencebetween 15 and 12?”

+1 +2 +3

0 1 2 3 4 5 6 7 8 9 10 11 12 13 1514

Page 14: Dale Calculations Policy

SubtractionStep 5:Children start to develop skills in counting on in tens and units/ones. Gurpreet works out the question, “56 subtract 23 equals what?”using both a number line and by jottings.

23 33 43 53

+10 +10 +10 +3

+10 + 10 + 10 + 3 = 33

56

Step 6:Children start to develop greater skills by partitioning groups of tens and groups of units/ones.“Eleisha wants to find the differencebetween 78 sweets and 43 sweets.She counts on from 43 up to 78.”

43

+30

73 78

+5

30 + 5 = 35 so 78 - 43 = 35

Page 15: Dale Calculations Policy

SubtractionStep 7:Children use complementary addition - counting up from the smaller number to the larger one including bridging through tens/hundreds.Luqman asks, “What is the answer to 164 minus 68?”Frantisek works it out using a number line adding together the jumps ~ 2+30+60+4 gives an answer of 96.

Children can progress to taking jumps even larger from 70 to 160 giving you: +2 + 90 + 4.

68 70 100 160 164

+2 +30 +60 +4

Step 8:Children move onto the more formal way of recording, but need to be very secure on the previous stages before trying to record in this manner.“Paul wants to find 74 subtract 27.”

70 +

+20 7

4

-

70 +

+20 7

4

-

60 14

+40 7

Page 16: Dale Calculations Policy

SubtractionStep 9:Children now use the formal method of “decomposition”, but need to be very secure on the previous stage before trying to record in this manner.

Kieran asks Noman, “Can you work out the subtraction of 256 from 725?”

Children should be in the habit of checking their answers by adding the answer to the number being taken away.469 + 256 = 725

6 11 15

7 2 5

- 2 5 6

4 6 9

Page 17: Dale Calculations Policy

SubtractionStep 10:Children can progress to using decomposition with decimals.“Henna has £34.60 and spends £15.36, how much has she got left?”

2 14 . 5 10

3 4 . 6 0

- 1 5 . 3 6

1 9 . 2 4

Page 18: Dale Calculations Policy

MultiplicationStep 1:Children will use pictures and symbols of every object to arrive at the total.“There are 2 sweets in a jar. How many sweets, are there altogether, in 4 jars?”

Children will first count individual sweets: 1, 2, 3, 4, 5, 6, 7, 8.

Step 2:Children will use pictures and symbols of every object to arrive at the total.“There are 3 sweets in a jar. How many sweets, are there altogether, in 5 jars?”

Children can use a number line to jump in threes.

0 1 2 3 4 5 6 7 8 9 10 11 12 13 1514

+3 +3 +3 +3 +3

Page 19: Dale Calculations Policy

MultiplicationStep 3:From pictures to notation using repeated patterns and repeated addition. “Eva has 4 lots of 3 pebbles. How many has she altogether?”

0 1 2 3 4 5 6 7 8 9 10 11 12

+3 +3 +3 +3

Page 20: Dale Calculations Policy

MultiplicationStep 4:Children recognise that repeated patterns can be represented in different ways. “Zaryab has 6 lots of 3 pebbles. How many has she altogether?”

6 lots of 3 (3+3+3+3+3+3)

0 1 2 3 4 5 6 7 8 9 10 11 12

+3 +3 +3 +3

13 14 15 16 1718

+3 +3

+6 +6 +6

or 3 lots of 6 (6+6+6)

Page 21: Dale Calculations Policy

MultiplicationStep 5:Children use number lines to work out multiplication questions.“8 children each have 4 playing cards. How many do they have altogether?”

8 lots of 4, can be written as, 8 x 4

20 2228324 8 12 160

Step 6:Children use partitioning to work out multiplication questions involving two digit numbers.

“28 children are given 4 sweets each, how many sweets are there altogether?”

28 = 20 + 8 (Partition the tens and units)

T U

x 20 8

4 80 32

= 8 0

+ 3 2

1 1 2

Page 22: Dale Calculations Policy

MultiplicationStep 7:Children use the grid method for multiplication of three digit figures by a single digit figure. “What is the product of 296 and 4?”

This is the same as “What is 296 multiplied by 4?” “What is 296 times by 4?” “What is 296 x 4?”

Children should be confident in the use and knowledge of times tables.

H T U

x 200 90 6

4 800 360 24

= 8 0 0

3 6 0

+ 2 4

1 1 8 4

Page 23: Dale Calculations Policy

MultiplicationStep 8:Children use the grid method for multiplication of three digit numbers by two digit numbers. “A school has 182 children, each child saves 48 pence. How much does the whole school collect?”

Change 8,736 pence to pounds and pence. Equals £87.36

H T U

x 100 80 2

40 4000 3200 80

8 800 640 16

4 0 0 0

3 2 0 0

8 0 0

6 4 0

8 0

+ 1 6

8 7 3 6

1 1

Page 24: Dale Calculations Policy

Step 9:Children progress to using the grid method for decimals.What is the product of 3.6 x 2.7?”

This is the same as“What is the product of 2.7 x 3.6?”

Estimate your answer 4 x 3 = 12

Multiplication

U t

x 3 0.6

2 6 1.2

0.7 2.1 0.42

6

2 . 1

1 . 2

+ 0 . 4 2

9 . 7 2

4x3=12

Page 25: Dale Calculations Policy
Page 26: Dale Calculations Policy

DivisionStep 1:They will start by sharing items out equally, to work out how many each child gets.

“Share 6 sweets equally between 3 children. How many does each child get?”

Page 27: Dale Calculations Policy

DivisionStep 2:Children start to draw pictures or make marks.

“Mr Kooner divides 12 children into teams of 3. How many teams are there?”

Page 28: Dale Calculations Policy

DivisionStep 3:Children start to recognise the symbol for division ÷ (8 ÷ 2).

“8 Sweets are shared between 2 children. How many do they both get?”

Each child gets 4 sweets.

Page 29: Dale Calculations Policy

DivisionStep 4:Children start to use a number line in grouping.

“There are 10 sweets. How many children can have two sweets each?”

How many 2’s make 10? (Inverse operation to multiplication & using knowledge of tables).

2 4 6 80 10

1 2 3 4 5

Step 5:Children use the multiple subtraction method to work out division with remainders.

“Liam has 17 sweets to share between 4 friends and himself. How many sweets do they each get and how many are left over?”

5

1 lot of 5

10

2 lots of 5

15

3 lots of 5

17

Remainder 2

17 ÷ 5 = 3 remainder 2

Page 30: Dale Calculations Policy

DivisionStep 6:Children use ‘chunking up’ on a number line to work out division.

Satinder works out the question, “135 divided by 4 equals what?” using both a number line and by jottings.

40 80 1200

x10 x10 x10 x2

128 132

x1

135

Don’t forgetto count any

remainder= 3

Add up how many ‘lots of 4’ you jumped: 10 + 10 + 10 + 2 + 1 = 33 r3

Step 7:Children continue to use the ‘chunking up’ method on a number line to work out division. They now use greater chunks:

Emily works out the question: “135 divided by 4 equals what?”

Add up how many ‘lots of 4’ you jumped: 30 + 3 = 33 r3

1200

x30 x3

132 135

remainder = 3

Use easy times tables

facts to help you: x4 facts:1 x 4 = 4 2 x 4 = 8 5 x 4 = 20

10 x 4 = 40

Page 31: Dale Calculations Policy

DivisionStep 8:Children progress to a more formal way of recording (called chunking):

“If 100 pence is shared equally between 7 children, how much does each child get?”

1 0 0

- 7 0 (10 x 7)

3 0

- 2 8 (4 x 7)

2

So 100 ÷ 7 = 14 r2

5 1 8

- 3 5 0 (50 x 7)

1 6 8

- 1 4 0 (20 x 7)

2 8

- 2 8 (4 x 7)

Leading to: 518 ÷ 7 =

So 518 ÷ 7 = 74

Page 32: Dale Calculations Policy

Times Tables

1 x 1 = 1

2 x 1 = 2

3 x 1 = 3

4 x 1 = 4

5 x 1 = 5

6 x 1 = 6

7 x 1 = 7

8 x 1 = 8

9 x 1 = 9

10 x 1 = 10

1 x 2 = 2

2 x 2 = 4

3 x 2 = 6

4 x 2 = 8

5 x 2 = 10

6 x 2 = 12

7 x 2 = 14

8 x 2 = 16

9 x 2 = 18

10 x 2 = 20

1 x 3 = 3

2 x 3 = 6

3 x 3 = 9

4 x 3 = 12

5 x 3 = 15

6 x 3 = 18

7 x 3 = 21

8 x 3 = 24

9 x 3 = 27

10 x 3 = 30

1 x 4 = 4

2 x 4 = 8

3 x 4= 12

4 x4 = 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

1 x 5 = 5

2 x 5 = 10

3 x 5 = 15

4 x 5 = 20

5 x 5 = 25

6 x 5 = 30

7 x 5 = 35

8 x 5 = 40

9 x 5 = 45

10 x 5 = 50

1 x 6 = 6

2 x 6 = 12

3 x 6 = 18

4 x 6 = 24

5 x 6 = 30

6 x 6 = 36

7 x 6 = 42

8 x 6 = 48

9 x 6 = 54

10 x 6 =60

1 x 7 = 7

2 x 7 = 14

3 x 7 = 21

4 x 7 = 28

5 x 7 = 35

6 x 7 = 42

7 x 7 = 49

8 x 7 = 56

9 x 7 = 63

10 x 7 = 70

1 x 8 = 8

2 x 8 = 16

3 x 8 = 24

4 x 8 = 32

5 x 8 = 40

6 x 8 = 48

7 x 8 = 56

8 x 8 = 64

9 x 8 = 72

10 x 8 = 80

1 x 9 = 9

2 x 9 = 18

3 x 9 = 27

4 x 9 = 36

5 x 9 = 45

6 x 9 = 54

7 x 9 = 63

8 x 9 = 72

9 x 9 = 81

10 x 9 = 90

1 x 10 = 10

2 x 10 = 20

3 x 10 = 30

4 x 10 = 40

5 x 10 = 50

6 x 10 = 60

7 x 10 = 70

8 x 10 = 80

9 x 10 = 90

10 x 10 =100

Dale Community Primary School