Gosfield Community Primary School
‘Building a love of life and learning’
Four rules Policy
Mental strategies and mental
strategies with jottings
Written strategies
Development matters/Early Learning Goals
4 rules Policy
1 to 1 correspondence
Counting objects
Vocabulary
Taking away 1
1 less object
Taking different numbers away
1 fewer object
Pictorial representation
Drawing 1 less
Number lines & tracks & Squares
Counting on number tracks
Counting on marked number lines
2
Subtraction
Ongoing
strategies
Partitioning
How many
Count back
(from, to)
Count in
ones, twos,
tens
Less
Take
Takeaway
Leave
How many
are left
How many
are left over
How many
are gone
One less,
two less, ten
less
How many
fewer
is…than..?
Difference
Estimating
4 rules Policy
Subtraction
between
change
Number bonds to 10
Mental strategies and mental strategies with jottings
8
Level 1
Units
Ones
Tens
Exchange
Digit
Teens
number
Subtract
Minus
How much
less is...?
Half, halve
Equals sign
Number
sentence
Sign
operation
Calculate
Calculation
10
2
Count back from the largest
number.
15 - 8 =
15, 14, 13, 12, 11, 10, 9, 8, 7
Taking away 11 and 9 by
rounding and adjusting
15 – 9 = 15 – 10 = 5
5 + 1 =6
Or
15 – 11 = 15 – 10 = 5
5–1=4
3
Recognise
standard
signs and
symbols.
4 rules Policy
Subtraction
Pictorial representation
Number lines & tracks & Squares
Written strategies
10 – 3 = 7
15 – 10 = 5
4
Partitioning
4 rules Policy
Partitioning of numbers to 10
Subtraction
One hundred Start with
less
the digit
greatest in
Tens
value
boundary
8–5=8–2–3=3
Subtracting 1 digit number to 20
(not bridging)
8 – 6 = 2 ∴ 18 - 6 = 12
Round
Mental strategies and mental strategies with jottings
Level 2
Number bonds to 20
Nearest
20
18
Round to the
nearest ten
2
Subtracting 10
Symbol
Subtracting 1 digit number
bridging through 10
Number
bonds
33 - 10 = 23
43 - 10 = 33
53 - 10 = 43
13 – 8 = 5
14 – 6 = 8
Use related facts
Near halves
15 – 8 = 7 ∴ 15 – 7 = 8
14 - 8 =
Half 14 = 7
∴
14 – 7 – 1 = 6
5
4 rules Policy
Subtraction
Number lines & tracks & Squares
Written Strategies
Pictorial representation
6
Partitioning
4 rules Policy
Subtraction
Subtracting single jumps on marked number line
Partitioning of numbers to
10
9–5=4
-1 -1 -1 -1 -1
8=5+3
Or
5
8
2
1
Subtracting single jumps on reduced number line
-1 -1 -1 -1 -1
8=5+ 2+1
Partitioning into tens and
units
Subtracting single jumps on an empty number line
-1 -1 -1 -1 -1
17
4
9
Subtracting tens and units on an empty number line
23 - 15 =
- 10
8
18
23
7
7
Or
17
-1 -1 -1 -1 -1
10
10
5
2
4 rules Policy
Subtraction
Number bonds
100 – 40 = 60
100 – 45 = 55
Partitioning
134 - 63 = 134 - 3 = 131
131 – 30 = 101
101 – 30 =71
Hundreds
boundary
Equation
Approximate
ly
Mental strategies and mental strategies with jottings
Level 3
Number line
Least
expensive
71
131 134
Greatest
value
Rounding and adjusting
118 - 54 = 120 - 54 – 2 = 64
Least value
Decrease
inverse
8
4 rules Policy
Subtraction
Number lines & tracks &
Squares
Partitioning
Partitioning into Hundreds Tens and Units
137
100
30
Expanded written method
429 – 276 =
7
9–6=3
20 – 70 can not do this ∴
Or
100
Written Strategies
Written Methods
120 – 70 = 50
20
137
300 – 200 = 100
10
5
100 + 50 + 3 = 153
2
Subtracting partitioned numbers
264 – 157 =
264 – 7 = 257
257 – 50 = 207
207 – 100 = 107
9
Mental strategies and mental strategies with jottings
Subtraction
Number bonds
1000 - 400 = 600
1000 – 450 = 550
1000 – 355 = 645
Units
boundary
Partitioning
1006 - 209.8 = 1006 - 0.8 - 9 - 200 = 796.2
Tenths
boundary
Number line
796.2 996.2
1005.2 1006
Rounding and adjusting
9.8 – 5.6 = 10 – 5.6 - 0.2 =
Multiplying and dividing by 10,
100, 1000
9.8 - 5.6 (x10)
Number lines & tracks &
Squares
= 98 - 56 = 42 (÷ 10)
= 4.2
Partitioning
Written Strategies
Level 4
4 rules Policy
Written Methods
Formal compact method
with carrying
3 1
0 1314 1
437264
1450 162
173
1288
1
10