Addition and Subtraction

Our Key Strategies for Addition and Subtraction

Strategy
Example
Place Value (Addition)
Splitting the numbers into parts
234 + 657 = 891
200 + 600 = 800
30 + 50 = 80
4 + 7 = 11
800 + 80 + 11 = 891

Place Value (Subtraction)
Splitting the numbers into parts using the big number first
89 – 36 = 53
89 – 30 = 59
59 – 6 = 53

Rounding and Compensating (Addition)
Adding a little bit on to make a tidy number then taking that little bit off at the end
145 + 28 = 173
28 + 2 = 30
145 + 30 = 175
175 – 2 = 173

Rounding and Compensating (Subtraction)
Adding a little bit on to make a tidy number then adding that little bit more on at the end to make up for taking too much off
175 – 99 = 75
99 + 1 = 100
175 – 100 = 75
75 + 1 = 75

Equal Additions (Subtraction)
Adding a small bit to the second number to make it a tidy number, then adding the same amount to the other number to adjust the adding
376 – 48 =
48 + 2 = 50      376 + 2 = 378
378 – 50 = 328

Reversibility (Subtraction)
Making a subtraction problem into an addition problem to make it easier to solve
33 – 26 = 7
26 + _ = 33
26 + 7 = 33


Addition and Subtraction Strategy video links:

Addition and Subtraction Strategy video links made by the children:

Decimal Adding and Subtracting Using Place Value:

Decimal adding using rounding and compensating:


Good addition games for year 2/3
https://www.tes.com/teaching-resource/teachers-tv-primary-maths-calculation-6038949 - maths games - dont get a six, race track, 4 rolls to a hundred

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