In order to encourage children to work mentally, calculations should always be presented horizontally so children can make decisions about how to tackle them.
Encourage children to choose to use the most efficient method for the numbers and the context. Teach operations together to emphasise the importance of inverse.
National Curriculum
Guidance
Addition To be taught alongside each other Subtraction
Vocabulary
Children will continue to use empty number lines with increasingly
Children will continue to use empty number lines with increasingly
,
add,
addition, more,
Pupils will be taught to:
larger numbers and will begin to use informal methods (jottings) to
large numbers and will begin to use informal methods (jottings) to
plus
support, record and explain partial mental methods, building on
support, record and explain partial mental methods, building on
existing mental strategies.
existing mental strategies.
make, sum, total
add and subtract
Pupils will practise solving
Counting back
altogether
Y3 numbers mentally,
Counting on
Subtracting the tens in one jump and the units in one jump (focus
score
varied
addition
and
on efficiency… e.g. challenge children to solve subtraction
including:
calculations in two steps) 147 -23 = 147 – 20 = 127 127 – 3 = 124
Count on from the largest number irrespective of the order of
double, near double
subtraction questions. For the calculation. Bridge through tens and begin to bridge through Bridging through ten can help children become more efficient.
one more, two more...
e.g. 147 – 63
100’s.
a three-digit number
mental calculations with
E.g. 38 + 86 = 124
ten more... one hundred
and ones
more
two-digit numbers, the
a three-digit number
how many more to
answers could exceed 100.
make…?
and tens
Counting on Use Finding the difference ITP between two numbers by
Compensation (for near multiples of 10) e.g. 49p + 73p = 122p
how many more is…
a three-digit number
counting on. Relate to every day contexts such as age, height, length
than…?
etc.
Pupils will use their
and hundreds
how much more is…?
understanding of place
subtract, subtraction,
add and subtract
value and partitioning, and
take (away), minus
Expanded informal method using place value (Introduce
numbers with up to
practise using columnar
leave, how many are
practically. Encourage children to use when the calculation can’t be
done mentally. Model first with simpler numbers which they can
three digits, using the
left/left over?
addition and subtraction
solve mentally).
one less, two less… ten
efficient written
with increasingly large
Where the numbers involved in the calculation are close together or
less… one hundred less
Model expanded horizontal partitioning with Base 10.
near to multiples of 10, 100 etc. counting on using a number line
methods of columnar
numbers up to three
how many fewer is…
should be used, alongside resources like bead bars. 102 – 89 = 13
67 = 60 + 7
addition and
digits to become fluent.
than…?
+24
20 + 4
subtraction
how much less is…?
91 = 80 + 11
difference between
estimate the answer to
half, halve
Compensation
(for
near
multiples
of
10)
63
–
8
=
55
243 = 200 + 40 + 3
+435 400 + 30 + 5
equals, sign, is the
a calculation and use
678 = 600 + 70 + 8
same as
inverse operations to
tens boundary,
check answers
hundreds boundary
solve problems,
Expanded informal method using place value
67 = 60 + 7
including missing
-24 - 20 + 4
number problems, using
43 = 40 + 3
Leading to the compact written method (see Y4)
number facts, place
Example: 74 − 27
value, and more
60
6 14
14
70  4
70  4
7 4
complex addition and
 20  7
 20  7
 2 7
subtraction.
40  7
4 7
add and subtract
fractions with the same
denominator within one
whole
[for example, 5/7 + 1/7 =
6/7 ]
Develop into 3 digit – 2 digit numbers modelling with Base 10.
Partition 3 digit numbers into ways that are helpful for the
subtraction. E.g. 325 – 58 = 325 – 25 - 25 – 5 – 3 = 267
Or 325 – 58 = 267 so 325 becomes 200 + 110 + 15
- 50 - 8
200 + 60 + 7
(Encourage children to use when the calculation can’t be
done mentally. Model first with simpler numbers which they can
solve mentally).
Encourage children to check results by using the inverse, using a different method e.g. equivalent calculation and by estimation where appropriate.
In order to encourage children to work mentally, calculations should always be presented horizontally so children can make decisions about how to tackle them.
Encourage children to choose to use the most efficient method for the numbers and the context. Teach operations together to emphasise the importance of inverse.
National Curriculum
Guidance
Addition To be taught alongside each other Subtraction
Vocabulary
Y4
add and subtract
numbers with up to 4
digits using the
efficient written
methods of columnar
addition and
subtraction where
appropriate
estimate and use
inverse operations to
check answers to a
calculation
solve addition and
subtraction two-step
problems in contexts,
deciding which
operations and
methods to use and
why.
Difference by counting on (See Y3) For numbers close together
E.g. 102 – 89 = 13
Expanded informal method
Pupils will be taught to:
67 = 60 + 7
+24
20 + 4
91 = 80 + 11
Pupils will continue to
practise both mental
methods and columnar
addition and subtraction
with increasingly large
numbers to aid fluency.
2000 +300 +20 +7
+500 +40 +2
2000 +800 +60 +9 = 2869
Model expanded horizontal partitioning with Base 10 leading to
compact vertical method working from left to right, then from right
to left.
67
67
+24
+ 24
80
11
11
80
91
91
625
+ 324
900
40
9
949
625
+ 324
9
40
900
949
2327
+ 542
2000
800
60
9
2869
2327
+ 542
9
60
800
2000
2869
Expanded horizontal (including 4 digit numbers) using base 10
Model how solving an addition on an empty number line
increasingly becomes less efficient as the complexity and size of
numbers increases.
Moving into compact method
involving fractions and
Compensation
Continue to teach compensation method where children round and
adjust to the nearest 10 / 100, especially in the context of money.
decimals to two
£4.99 + £6.99 = £5.00 – 1p + £7.00 – 1p = £12.00 – 2p = £11.98
decimal places.
Counting back and Compensation When appropriate (using number
lines) bridging through 10, 100 and 1000 and rounding and adjusting
(compensating) e.g. 42p – 5p or 193 litres – 18 litres or £823 – £32
or 706mins – 28mins or 307cm – 111cm or 1006km - 9km
Moving quickly into 3 or 4 digit numbers for calculations that are
hard to solve mentally.
solve simple measure
and money problems
Including measures e.g.
754ml – 690ml or 1275g – 786g or £3.00 - £2.68
Using similar methods, children will:

add several numbers with different numbers of digits;

begin to add two or more three-digit sums of money, with
or without adjustment from the pence to the pounds;

know that the decimal points should line up under each
other, particularly when adding or subtracting mixed
amounts, e.g. £3.59 + 78p.

754 = 700 + 50 + 4
=
700 + 40 + 14
=
600 + 140 + 14
- 200 80 6
400 60 8
Children should:

be able to subtract numbers with different numbers of
digits;

begin to find the difference between two three-digit sums
of money, with or without ‘adjustment’ from the pence to
the pounds;

solve with increasing efficiency using only two steps
Encourage children to check results by using the inverse, using a different method e.g. equivalent calculation and by estimation where appropriate.
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
inverse