how children learn (and we teach) the four operations
TRANSCRIPT
How children learn (and we teach)
the Four Operations
To understand expectations of the new curriculum in mathematics.
To be familiar with methods used for addition and subtraction
To become familiar with methods used for multiplication and division
To clarify progression
Aims
The Hat Game
3
The New Curriculum for mathematics aims to ensure that all pupils:become fluent in the basics of mathematicsreason mathematically can solve problems by applying their mathematics to a variety of routine and non-routine problems with increasing sophistication
The New Curriculum for mathematics
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Your feelings of maths
1999+ 2009 312 x 54 1850 ÷ 25 2786 – 1899 178.45 x 13 4782 ÷ 13 2345 + 2346
Consider for a moment…
15 – 5 = 29+11=18 – 16 = 2007 – 1992 =
359 – 211 =
1997 +33 =
6+4+7 =24.6 – 12.4 =
How would you approach these questions?
Little Big Maths ~ Jupiter Class
CLIC ~CountingLearn ‘It’s facts’ (no bonds)‘Its nothing new’ (applying)Calculations (Methods =, + , - ,x , division)
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We may have been taught different ways at school
387 + 564
ADDITION
Counting on
Number Lines (Progression)
•Numbered lines
•Bead strings
•Partly numbered lines
Counting On
Not crossing tens boundary
e.g. 34 + 23
Jumps of 10s and 1s
Encourage children to become more efficient
•Add 3 in 1 jump
•Add 20 in 1 jump
Crossing tens boundary
e.g. 37 + 25
Jumps of 10s and 1s
Help children become more efficient:
Add 5 in jumps of 3 and 2
(bridging over 10) Add 20 in 1 jump
Counting on
476+973= 476+ 973-------------- 9 (6 + 3) 140 ( 70 + 70) 1300 ( 900 + 400)---------------- 1449
Column addition
476+973=
400 + 70 + 6900 + 70 + 3------------------
1300 + 140 + 9= 1449
We only use these if children are able to manipulate numbers and have a good understand
of place value
Compact (Formal) method New Curriculum
Accurate use of language is key.
7 8 9+ 6 4 2 1 4 3 1 1 1 (These are carried)
SUBTRACTION
Using a numberline for larger numbers ~
using find the difference
74 – 27 = 47
+ 3+ 40
+ 4
27 30 70 74
74 – 27 = 40 + 4 + 3 = 47
368 - 152 216
No ‘borrowing’
Formal written method
932-457
9 3 2 - 4 5 7 4 7 5
Compact Formal method New Curriculum
1218
Multiplication
Slide 2.18
Counting sticks Repeated addition Rapid recall of multiplication tables facts
Games Good as oral / mental starters Using known facts (e.g. doubling)
Arrays
Early Multiplication
Grid method 26 x 7
Moving on with MultiplicationProgression
2 digit x 1 digit 3 digit x 1 digit3 / 4 digit x 2 digit
30
2
10
300
20
20
6
7
140
42
=182
4
32 x 14
120 420
8 28
= 448
3 4 2 x 7 2 3 9 4 2 1
Formal Methods – New curriculum
1 2 4 x 2 6 7 4 4 1 2
2 4 8 0
3 2 2 4
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Division
Children appear to find sharing (partitive) tasks easier but this becomes inefficient with larger numbers,
e.g. 196 Smarties divided by 6 children – on a one for you, one for me basis this takes a while!!!
We therefore need to help children to move from sharing individual items to groups of items,
e.g. We could do 20 for you, 20 for me etc, we are taking away groups of the divisor from the dividend (CHUNKING).
Dividing - Sharing and grouping
Children’s working
A tent holds 6 children.How many tents are needed to hold 70 children?
48 ÷ 6 =
Number line division
1 x 6 1 x 6 1 x 6 1 x 6 1 x 6 1 x 61 x 61 x 6
0 24 30 36 42 486 12 18
To divide 81 by 3
20 x 3 7 x 3
0 60 81
Remainders
17 ÷ 5 = 3 r 2 or 3 2
5
1050 17
555
15
5
2
200 1715105
r2
126 72
60 10 x 6 12
12 2 x 6 0
Chunking
Slide 2.28
Formal method – short and long division
New curriculum
1 4 2
7 9 8
2 8 r 12
1 5 4 3 2 3 0 0 1 3 2 1 2 0 1 2
Progression chartLearning through play
Helping at home ~ Early years/KS1
Maths help at home ~ KS2
Slide 2.30