Step 5 Objective
Consolidate and extend mental methods of calculation to include decimals, fractions and percentages, accompanied where appropriate by suitable jottings; solve simple word problems mentally.
- Examples of what pupils should
know and be able to do - Probing questions
- What if pupils find
this a barrier?
Examples of what pupils should know and be able to do
Use factors. For example:
- 3.2 × 30 = 3.2 × 10 × 3
- 156 × 6 = 156 × 3 × 2.
Use partitioning. For example:
For multiplication, partition either part of the product:
7.3 × 11 = (7.3 × 10) + 7.3
= 80.3
Use 
= 0.2 to convert fractions to decimals mentally. For example: 
= 0.2 × 3 =0.6
Use mental calculations. For example:
of 20 = 2.5 (e.g. find one quarter and halve it)- 75% of 24 = 18 (e.g. find 50% then 25% and add the results)
- 15% of 40 (e.g. find 10% then 5% and add the results)
- 40% of 400kg (e.g. find 10% then multiply by 4).
- FTM(S)Y789 p. 92 - Acrobat pdf document (44Kb)
- FTM(S)Y789 p. 94 - Acrobat pdf document (32Kb)
- FTM(S)Y789 p. 96 - Acrobat pdf document (26Kb)
- FTM(S)Y789 p. 98 - Acrobat pdf document (30Kb)
- FTM(S)Y789
p. 100 - Acrobat pdf document (29Kb)
- Thinking Fractions question - Rtf (rich text format) document (20Kb)