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Sparks
5
Teacher chooses range of starting numbers. Pupils
find decimal fractions
(1 and 2 d.p) of each one. |
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- Carry out calculations
using brackets and memory; use the square root and
sign change keys. Interpret the calculator display
in different contexts (decimals, percentages)
- Calculate simple fractions of quantities and measurements
(whole-number answers); multiply a fraction by an
integer |
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Last
year, there were 4000 house sales in Birmingham.
If there were a 35% increase this month, how many
were sold?
How would you solve this as a %? as a fraction?
as a decimal?
Which is easiest to use mentally? In writing?
On a calculator?
How would you check?
Use to summarise methods learnt so far.
How do written and mental methods differ?
How do you decide which is 'best' one?
Emphasise that:
1. range of complexity requiring
different methods:
mental methods 
jottings
written method
calculator method;
2. checking by estimating;
3. simplify fractions
by cancelling. |
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Simple
calculations with FDP
- to include mental, written and simple calculator
methods for fractions, decimals and percentages.
Eg: Starting with 5040, find these fractions:
1/2, 2/3, 3/4, 2/5, 5/6, 3/7.
Simple problems with FDP
- to include simple word problems, requiring mental
written and simple calculator methods.
Eg: large wedding cake
weighs exactly 5040g. 5/14 is sugar. What fraction
is not sugar? Decimal? Percentage?
How much do the remaining ingredients weigh?
Simple problems involving multiplication and division
(Link with Unit N5a)
- to include some mental, written and simple calculator
methods for multiplication and division. |
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11/14
of Year 11 have chosen to stay on in the 6th form.,
10 have chosen a different college and 2 pupils
have not yet decided. What fraction has not chosen
to stay on?
How many pupils are in 11C?
Use to discuss:
- methods
- efficiency of methods
- checking |
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pp. 66 –
68
(pp. 90 – 108 calculations) |
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What
is:
50% of 2/3?
3/8 of 50% of 2/3?
0.12 of 3/8 of 50% of 2/3?
Continue as appropriate.
What order did you tackle the last question in? |
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- Break a complex
calculation into simpler steps, choosing and using
appropriate and efficient operations, methods and
resources, including ICT.
- Carry out calculations using brackets and memory;
use the square root and sign change keys. Interpret
the calculator display in different contexts (decimals,
percentages). |
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See
example above.
If next month's sales drops again by 35%, will this
mean there will be 4000 sales this month?
Explain your answer.
Discuss how to break problem down to simple steps.
Aim is to apply skills with simple numbers and contexts
to more demanding ones. and to decide which methods
and operation to use.
Emphasise that:
1. most number problems that pupils will meet will
include FDP, and the 4 operations.;
2. range of complexity requiring different methods:–
mental methods
jottings
written method
calculator method;
3. This lesson focuses on calculator methods for
more complex problems.
(Link to Unit N5a Long multiplication and division). |
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More
complex problems with FDP
Range of problems needing calculator methods involving
FD and P:
Eg: A large wedding cake
weighs exactly 5.04g. 2/5 is sugar, 1/3 is flour,
3/10 is butter, 2/7 is eggs and the rest is dried
fruit.
What percentage is dried fruit? (Minimum number
of calculator steps?)
More complex problems involving
multiplication and division
Range of problems needing calculator methods involving
multiplication and division. |
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36%
of £480?
Suggest a problem that this could represent
- with just 1
-step;
- with 2 steps;
- with 3 steps;
- with 4 steps.
Encourage a range of contexts and units.
Eg: delegate one of following to groups of pupils:
length, area, volume, mass, capacity, time
Review the range of methods used. |
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