Our Key Strategies for Addition and Subtraction
Strategy
|
Example
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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:
https://www.educreations.com/lesson/view/rounding-and-compensating/37718789/?s=jnDSYc&ref=link
https://www.educreations.com/lesson/view/4-982-6/37718587/?s=GYGo8b&ref=link
https://www.educreations.com/lesson/view/4-982-6/37718587/?s=GYGo8b&ref=link
https://www.educreations.com/ lesson/view/rounding-and- compensating/37881835/?s= fEPzk0&ref=app
https://www.educreations.com/ lesson/view/rounding-and- compensating/37834245/?s= Q9cPdM&ref=link
https://www.educreations.com/
Decimal adding with an algorithm
https://www.educreations.com/lesson/view/math/37720229/?s=Yb8YnL
https://www.educreations.com/lesson/view/how-to-add-and-sub-decimals/38326469/?s=ZysZlI&ref=link
https://www.educreations.com/lesson/view/math/37720229/?s=Yb8YnL
https://www.educreations.com/lesson/view/how-to-add-and-sub-decimals/38326469/?s=ZysZlI&ref=link
Decimal adding using place value:
https://www.educreations.com/lesson/view/decimals/37887436/?s=HlVigX&ref=link
https://www.educreations.com/lesson/view/decimals/37887436/?s=HlVigX&ref=link
Decimal subtraction with equal additions:
https://www.educreations.com/lesson/view/equal-additions/37883007/?s=STB2CW&ref=link
Decimals subtraction with algorithms:
https://www.educreations.com/lesson/view/subtracting-with-decimals/38326290/?s=fmwpqU&ref=link
https://www.educreations.com/lesson/view/equal-additions/37883007/?s=STB2CW&ref=link
Decimals subtraction with algorithms:
https://www.educreations.com/lesson/view/subtracting-with-decimals/38326290/?s=fmwpqU&ref=link
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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