progression in maths - calculation methods
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x. -. ÷. +. Progression in Maths - calculation methods. Abbey Primary School – December 2012. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
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Abbey Primary School – December 2012
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Written methods of calculations are reliable and efficient procedures which can be used in many different contexts. However, they are of no use to someone who applies them inaccurately or who cannot judge whether the answer is reasonable.
The progression towards a written method is crucial, since it is based on steps which are done mentally and which need to be secured first.
A structured approach to developing written methods relies on:
1) Apparatus
2) Apparatus + picture
3) Apparatus + picture + recording
4) Picture + recording
5) Recording
Developing a common whole school approach enhances pupils’ confidence and aids continuity across the school.
It can be hard for a pupil to hold all the steps of a calculation in their heads, so informal jottings should be encouraged at all times.
The transition between stages should not be hurried as not all children will be ready to move on to the next stage at the same time, therefore the progression in this document is outlined in stages. Previous stages may need to be revisited to consolidate understanding when introducing a new strategy.
Introduction
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Progression in Teaching Addition
Mental Skills
Recognise the size and position of numbersCount on in ones and tensKnow number bonds to 10 and 20Add multiples of 10 to any numberPartition and recombine numbersBridge through 10
Models and Images
Counting apparatus Place value apparatusPlace value cardsNumber tracksnumiconNumbered number linesMarked but unnumbered number linesEmpty number linesHundred squareCounting stickBead stringModels and Images chartsITPs – Number Facts, Ordering Numbers, Number Grid, Counting on and back in ones and tens
Key Vocabulary
add additionplus andcount ongreatermoreMostsumtotal altogetherincrease
40 8
4
1, 2, 3, 4, 5, 6 … there
are 6 teddies
Recognise numbers 0 to 10
Cardinality: Knowing that 6 objects is the number 6.
Count reliably up to 10 everyday objects
Find one more than a number One more than three is
four
Count all
Count in ones and tens
Count on (keeping number in your head / hiding the first
pattern) 3 + 2 =
5
Begin to use the + and = signs to record mental calculations in a number
sentence6 + 4 =
10
Know doubles of numbers and their corresponding halves
5
Know by heart all pairs of numbers with a total of 20
Know that addition can be done in any order
1 9 2 8 3 7 4 6 5 5
Put the biggest number first and count on
Begin to partition and recombine numbers in
order to add
3 +
5 5 8
+ 3
6
Know which digit changes
when adding 1s or 10s to any
number
15 + 1 = 16
15
15
15 + 10 = 25
15 + 20 = 35
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Adding two two-digit numbers (bridging through tens boundary)
Using a number line 48 8478
+30
80
+2 +4
48 + 36 = 84
Adding two two-digit numbers (without bridging)
Counting in tens and ones
15 + 13 = 28
15 + 10 + 3 = 28
15 25 28
15 16 17 18
25 26 27 28
25 35
25
16
48 + 30 + 6 = 84
7
48 + 36 = 84
T U
40 + 8
+ 30 + 6
80 + 4
10
It is important that the children have a good understanding of
place value and partitioning using concrete resources and visual
images to support calculations. The expanded method enables children to see what happens to numbers in the standard written
method.
T U
Remember to add the least significant digits (e.g. units in this case)
first
48 + 36 = 84
Adding two two-digit numbers (bridging through tens boundary)
Using place value cards and place value apparatus to partition
numbers and recombine
48
+ 36
14 (8 + 6)
70 (40 + 30)
84
40 8 30 6
8
225 + 156 = 381
200 + 20 + 5
+ 100 + 50 + 6
300 + 80 + 1
10
2 2 5 +1 5 6 3 8 1 1
4 8
+ 3 6
8 41
Standard written methodThe previous stages reinforce what happens to the numbers when they are added together
using more formal written methods.
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Progression in Teaching Subtraction
Mental Skills
Recognise the size and position of numbers Count back in ones and tensKnow number facts for all numbers to 20Subtract multiples of 10 from any numberPartition and recombine numbers (only partition the number to be subtracted)Bridge through 10
Models and Images
Counting apparatusPlace value apparatusPlace value cardsNumber tracks Numbered number linesMarked but unnumbered linesHundred squareEmpty number lines.Counting stickBead stringsModels and Images ChartsITPs – Number Facts, Counting on and back in ones and tens, Difference
Key Vocabulary
Subtract take away (specific use)minuscount backless fewerdifference between
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10
Begin to count backwards in familiar contexts such
as number rhymes or stories
Continue to count back in ones from any given
number
Take away
Find one less than a number
Count back in tens
Ten green bottles hanging on the wall …
Five fat sausages frying
in a pan …
Count backwards along a number
line to ‘ take away
If I take away four shells there are six
left
Three teddies take away two teddies leaves
one teddy
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Begin to use the – and = signs to record mental
calculations in a number sentence
6 - 4 = 2
Maria had six sweets and she ate four. How
many did she have left?
Know by heart subtraction facts for numbers up to 10 and 20
Begin to find the difference
40 – 27 = 13
27 4030
+ 1 + 10+ 1 + 1
28 29
Find the difference using the number line
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Find the difference using the number line
74 - 27 = 47
Extend to 3 digit numbers and decimals
40 – 27 = 13
27 30 40
+ 3 + 10
Find the difference using the number line
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Expanded method
It is important that the children have a good understanding of
place value and partitioning using concrete resources and visual
images to support calculations. The expanded method enables children to see what happens to numbers in the standard written
method.
40 + 3
- 20 + 7
10 + 6
10 +30
4 3
- 2 7
1 6
1 3
to subtract 7 units we need to
exchange a ten for ten units
43 - 27 = 16
Standard written methodThe previous stages reinforce
what happens to numbers when they are subtracted using more
formal written methods. It is important that the children have a good understanding of place
value and partitioning.
43 – 32 = 11
4 3- 3 2 1 1
40 + 3- 30 + 2 10 + 1
Extend to 3 digit numbers without exchanging.
column subtraction (without exchanging)
column subtraction (with exchanging)
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Progression in Teaching Multiplication
Mental Skills
Recognise the size and position of numbers Count on in different steps 2s, 5s, 10s Double numbers up to 10Recognise multiplication as repeated additionQuick recall of multiplication factsUse known facts to derive associated factsMultiplying by 10, 100, 1000 and understanding the effectMultiplying by multiples of 10
Models and Images
Counting apparatusPlace value apparatusArrays100 squaresNumber tracks Numbered number linesMarked but unnumbered linesEmpty number lines.Multiplication squaresCounting stickBead stringsModels and Images chartsITPs – Multiplication grid, Number Dials, Multiplication Facts
Vocabulary
lots ofgroups oftimesmultiplymultiplicationmultipleproductonce, twice, three timesarray, row, columndoublerepeated addition
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Count in tens from zero
Count in twos from zero
Count in fives from zero
Know doubles and corresponding halves
Know multiplication tables to 10 x 10
x 5 6 x 5 =
30
Use known facts to work out new ones
2 x 5 = 10
8 x 5 = 40
3 x 5 = 15
864 20 10
0 5 10 15 20 25 30
0 20 30 40 5010
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Understand multiplication as repeated addition 2 + 2 + 2 + 2 = 8
4 x 2 = 8
2 multiplied by 4
4 lots of 2
Understand multiplication as an array
Understand how to represent arrays on a number line
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Use place value apparatus to support the multiplication of U x TU
13 x 4 = 52
Use place value apparatus to support the multiplication of U x TU alongside the grid method
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10 3
4
10 3
40 12
40 + 12 = 524
10 3
40 12
4
10 310
23 x 4 = 92
Use place value apparatus to represent the
multiplication of U x TU alongside the grid method
80 + 12 = 92
13 x 4 = 52
1280
20 3
4
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Multiplying TU x TU
104
30 3
300
120
30
12
33 x 14 = 462
300
120
30
+ 12
462
Use same method to multiply HTU X U
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Progression in Teaching Division
Mental Skills
Recognise the size and position of numbers Count back in different steps 2s, 5s, 10s Halve numbers to 20Recognise division as repeated subtractionQuick recall of division factsUse known facts to derive associated factsDivide by 10, 100, 1000 and understanding the effectDivide by multiples of 10
Models and Images
Counting apparatusArrays100 squaresNumber tracks Numbered number linesMarked but unnumbered linesEmpty number lines.Multiplication squaresModels and Images chartsITPs – Multiplication grid, Number Dials, Grouping, Remainders
Vocabulary
lots ofgroups ofsharegrouphalvehalfdividedivisiondivided byremainderfactorquotientdivisible
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20
Count on in tens
Count on in twos
Count on in fives
Know halves
Use known multiplication facts to work out corresponding division
facts
Half of 6 is 3
½ of 6 = 3
If 2 x 10 = 20
then20 10 = 220 2 = 10
0 20 30 40 5010
864 20 10
201510 50 25
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Understand division as sharing
Understand division as grouping
Reinforce division as grouping through the
use of arrays
12 divided into groups of 3 gives 4
groups
12 3 = 4
12 divided into groups of 4 gives 3
groups
12 4 = 3
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18 4 = 4 r 2
Represent ‘groups’ for division on a number line
using apparatus alongside the line
0 18
18 divided into groups of 3
18 3 = 6
Remember to ask the question – how many groups of 3 in 18?
Introduce remainders
0 3 6 9 12 15 18
0 4 8 12 16 18
1 x 4 1 x 4 1 x 4 1 x 4 r 2
How many groups of 4s in 18? There are 4 groups of 4 with 2 left over.
3 6 9 12 15
1 x 3 1 x 31 x 31 x 31 x 3 1 x 3
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Children need to see that as the numbers get larger, chunking groups is the more efficient
method.
65 5 = 13
0 50 65
10 x 5 3 x 5
50 15
How many groups of 5 in 65?There are 13 groups of 5 in 65?