Examples of what pupils should know and be able to do
Complete statements such as:
4 ÷ 10 = 
4 ÷ = 0.04
0.4 × 10 = 0.4 × = 400
0.4 ÷ 10 = 0.4 ÷ = 0.004
÷ 100 = 0.04 ÷ 10 = 40
× 1000 = 40,000 × 10 = 400
Probing questions
Why do 25 ÷ 10 and 250 ÷ 100 give the same answer?
This calculator display shows 0.001. Tell me what will happen when I multiply by 100. What will the display show?
I divide a number by 10, and then divide the result by 10. The answer is 0.3.
What number did I start with? How do you know?
How would you explain to someone how to multiply a decimal by 10 . . . , how to divide a decimal by 100? . . .
What if pupils find this a barrier?
Use units that pupils are confident with, for example conversions between cm and m.
Encourage pupils to use common sense, e.g. 0.67 × 100. Is the answer larger or smaller?
- TL4Y7 Number 4 N4.1 - Acrobat pdf document (61Kb)
- TL5 Snapper 1 and 2 - Microsoft word document (39Kb)
Moving digits ITP - Zip file (457Kb) can be used to show that it is the digits that 'move' and not the decimal point.
Use Teaching mental calculation strategies loop cards set 10 - Acrobat pdf document (25Kb) to practise
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