Transcript File - Ysgol Owen Jones

Ysgol Owen Jones
Presentation of Written Calculation
Methods
Aims of Policy
• To raise awareness in the methods used in
school of written calculations
• To illustrate the progression of calculation
methods that children will meet.
• To explore activities of reasoning and problem
solving that children will meet.
Addition
• Children encourage to visualise the number
system through using Numicon, objects and
number lines
• 8 + 5 = 13
• Use of number lines – numbered and then
blank 34+23=57
• Year 3 – empty number lines with larger
numbers
• 58+86 = 124
+50
• 86
• 49 + 73 = 122
+4
+4
116
120
124
73+50 =123 -1 =122
• Horizontal Partitioning
• 67+24=91
• 60+20 = 80
7 + 4 = 11
=91
Vertical Methods
• 76
+ 47
____
110
13
_____
123
76
+ 47
_____
13
110
______
123
76
+ 47
_______
12 1 3
Decimal point is in line
Subtraction
• Early methods the same except counting
backwards.
• Decompositon 25 – 13 using Numicon or base
10
• 25 -16
Formal Subtraction
• Decompostion
• 56 145 11
8 6
_________
5 6 5
Multiplication
• Practical activities grouping sets
• Counting in 2s 5s 10s
• Use of Numicon
• Repeated addition on a number line
• 4x6=6+6+6+6
• Model with arrays
Grid method
• Short multiplication TU x U
23 x 8
20 3
8 160 24 = 160
24
------184
Long multiplication
•
•
•
70 2
30 2100 60
8 560 16
2100
560
60
16
______
2736
Division
• Practically
• Repeated Division
• 72 3
•
•
•
•
•
•
•
•
3 ) 72
-30
42
- 30
12
6
6
6
0
10
10
2
2
Answer 24