Year 5 Autumn 1 Week 3 – Written Addition and Subtraction (including problem solving)
Main Learning
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Add and subtract whole numbers with more than 4 digits and decimals with two decimal places,
including using formal written methods (columnar addition and subtraction).
Choose an appropriate strategy to solve a calculation based upon the numbers involved (recall a
known fact, calculate mentally, use a jotting, written method).
Use estimation and inverse to check answers to calculations and determine, in the context of a
problem, an appropriate degree of accuracy.
Solve addition and subtraction multi-step problems in contexts, deciding which operations and
methods to use and why.
Success Criteria
Vocabulary
add, addition, more, plus, increase, sum, total, altogether, score, double,
near double, how many more to make…?, subtract, subtraction, take
(away), minus, decrease, leave, how many are left/left over?, difference
between, half, halve, how many more/fewer is… than…?, how much
more/less is…?, equals, sign, is the same as, tens boundary, hundreds
boundary, units boundary, tenths boundary, inverse
Modelling
Practice and Consolidation
Teachers should refer to the school’s agreed progression towards written calculations policy. An
example can be found here.
Children should be given time to ensure the processes involved in the written methods are secure and
understood.
Choose a Strategy
Digit Reversal
Estimate and Calculate
Children will have come across formal written addition and subtraction in
previous year groups. However, some children may still need to represent
the calculation practically or visually.
When children are making decisions about choosing appropriate
strategies, model the thinking by talking them through different
possibilities.
3009 – 1995=
ICT
Although this may look suitable for a written method, both numbers are
close to thousand boundaries. Counting up on a number line will produce
a quick answer. Children should learn how to identify the most efficient
way to perform a calculation without always reverting to a written
method.
5
1995 2000
Mathematics - Planning Support © Lancashire County Council (2015)
1000
9
3000
3009
Using and Applying
Contextual Learning
Write in the missing digits:
If children set this calculation out
vertically, they can then think about
which calculations have produced the
answer 851.
Now look at the calculation on the right
What range of answers can you find?
Calculations should be in contexts including money, measures, real life problems and
number enquiries. Finding the perimeter of irregular shapes and finding missing lengths
when given the perimeter are good examples
of using addition and subtraction.
4
4
+ 3 8
8 5 1
7_54 – 465 =_____
Emily buys two scarves and a hat.
What is the most she could pay?
What is the smallest/largest difference you could make?
What is the same about every answer and what is different? Explain why.
Calculation Investigation!
Write additions and subtractions using near multiples of 100, e.g.
Assessment
231 + 199 = 430
231 – 199 = 32
Work out 3275 – 1837, explaining every step that you write.
Find the digital root of the starting number, e.g. the digital root of 231 is 2 + 3 + 1 = 6 and
the digital root of each answer, e.g. 4 + 3 + 0 = 7. Try adding and subtracting near multiples
of 100 to other 3-digit numbers. Find the digital root of the starting number and the
answers. What do you notice? Does this always happen?
Place the digits 0-9 to make this calculation correct:
 -  = 
0
5
Choose any four numbers from the grid
and add them.
Find as many different ways as possible
of making 1000.
Mathematics - Planning Support © Lancashire County Council (2015)
1
6
2
7
3
8
4
9
Make up an example of an addition involving decimals that you would do in your head and
one that you use a formal written method for. Explain why.
Two numbers have a difference of 1.58. One of the numbers is 4.72. What is the other?
Is this the only answer?
Two adults and two children go to a cinema. Adult tickets cost £5.85 and children's tickets
cost £2.85. How much change will they get from a £20 note?
Max jumped 2.35 metres on his second try at the long jump. This was 68 centimetres
longer than on his first try. How far in metres did he jump on his first try?
The Smith family has saved £675 towards their summer holiday.
The cost of the holiday is £2019. How much more do they need to save?
Tick the two numbers which have a total of 10.
Subtract 345.67 from 765.43