Transcript Stages in subtraction - Darrick Wood Infant and Nursery School

Maths workshop – Subtraction
Monday 22nd March 2010
The National Numeracy Strategy provides a structured and systematic approach to
teaching number. There is a considerable emphasis on teaching mental calculation
strategies and speaking and listening activities. Informal written recording always
takes place regularly and is an important part of learning and understanding. More
formal written methods should follow only when the child is able to use a wide
range of mental calculation strategies. This will help communicate methods and
solutions.
Stages in subtraction (these are not necessarily hierarchical)
•
Informal counting strategies e.g. counting songs, rhymes and games
•
Practical and pictorial subtraction
•
Use of number lines to count back from one number to another
•
Finding the difference between groups of objects or numbers
•
Using an empty number line to count back
•
Using an empty number line to count up
Stages in Subtraction by Decomposition
563 - 241 :
-
leading to:
500
60
3
200
40
1
300
20
2 = 322
5
6
3
-2
4
1
3
2
2
563 – 278:
-
500
60
3

400
150
13
200
70
8

200
70
8
200
80
5
= 285
leading to:
15 6
13
-2
7
8
2
8
5
45
Children’s own recording
Vocabulary
Subtract, subtraction, minus, take away, less, leave, fewer, decrease, difference
Equals
Number sentence
Record, draw, show me, jottings
Sum!
Resources to help children with subtraction
Ideas for subtraction activities at home
•Counting back in 1s, 2s, 5s, 10s, ……. from different starting points
•Using/making number lines to count back or count up
•Finding the difference between groups of objects e.g. toys
•Playing shops and giving change
•Solving subtraction problems
•Encouraging children to record subtraction problems in their own way and explain them to
you
•Asking children to talk you through the methods they have used at school
Any questions?
Please feel free to look at the children’s work, resources and maths vocabulary on display.
Miss Seare and I will be pleased to speak to you afterwards if you have any further comments
or questions.