teaching written calculations st. augustine’s catholic primary
TRANSCRIPT
TEACHING WRITTEN CALCULATIONS
St. Augustine’s Catholic Primary
Introduction
• Common approach – so the children don’t get confused
• Mainly start recording fromY1 onwards• Stages relate to year groups but not all
children at year group level• Cover all calculations today – am available
afterwards, or speak to class teacher• Presentation on school website
ADDITIONStage 1 –Teachers demonstrate
number lines8 + 5 = 13
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Stage 2 – Children use empty number lines starting with the
largest number and counting on
34+23 = 57
34 44 54 55 56 57
34 44 54 57
34 54 57
Stage 3
Make sure children count from largest number first.
Example
38 + 86 = swap to
86 + 38 =
Children begin to work in columns
6 7
+ 2 4
1 1 (7+4)
8 0 (60 + 20)
9 1
Stage 4 – Children begin to carry below the line
7 8 3
+ 4 2
8 2 5
1
Stages 5 and 6
Children use larger numbersChildren use decimal numbers
Have a go!!
How would you use a number line to demonstrate 28 + 54 =
Use the column method to calculate345 + 67 =
SUBTRACTIONStage 1 – Teachers demonstrate
number lines
13 – 5 = 8
0 1 2 3 4 5 6 7 8 9 1011 12 131415
Stage 2 – Children use empty number lines
47-23 =
24 25 26 27 37 47
24 27 37 47
24 27 47
Counting on
82-47 =
47 48 49 50 60 70 80 81 82
Stage 3 – Children use column method71 – 46 =
7 0 1
- 4 0 6
Stages 4,5 and 6 – Larger numbers, leading to short method
7 5 4
- 2 8 6
Have a go!!
How would you use a number line to demonstrate 58 – 24 =
Use the short column method to calculate 654 – 482 =
MULTIPLICATION – Stage 1 and 2Children must understand that
multiplication is repeated addition
5x3 =5+5+5
0 5 10 15
Need to understand that:
3x5 is the same as 5x3
0 3 6 9 12 15
Stages 3 and 4 – Children continue to use number lines and arrays
X 1 0 4
6
Grid method
23 x 8 =
x 2 0 3
8 1 6 0 2 4
1 6 0
+ 2 4
1 8 4
Short method38 x 7 =
3 8
x 7
2 6 6
5
Grid method for TU X TU
X 5 0 6
2 0 1 0 0 0 1 2 0
7 3 5 0 4 2
1 3 5 0 1 6 2
1 3 5 0
+ 1 6 2
1 5 1 2
1
Stages 5 and 6 – Short method
56 x 27 =Children approximate first:
60 x 30 = 1800
5 6
X 2 7
3 9 2 56x7
1 1 2 0 56x20
1 5 1 2
1
Have a go!!!
Use the grid method to calculate43 x 6
Try the short method
Calculate 56 x 43 using the grid method and short method
DIVISION – Stage 1 and 2 –Children understand that division
is repeated subtraction -4 groups of 3 in 12
12 3 = 4
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Stage 3 – Children continue to use repeated addition on number lines
including remainders13 4 = 3 r 1
0 1 5 9 13
Stage 4 – Short division using chunking method72 3 = 24
3)72 - 30 10 x 42 - 30 10 x 12 - 6 2 x 6
6 2 x Answer = 24 0
Stages 5 and 6 – Children use larger multiples and numbers
864 24 = 36
24)864- 720 30 x
144 - 72 3 x 72 - 72 3 x Answer = 36 0
Other Year 6 methods
Please look at the leaflets/website. These are used if children are having difficulties with the chunking method
Have a go!!
Use a number line to demonstrate 14 7 = 2
Use the chunking method to work out
65 5 =210 15 =