Use equivalence and compensation to simplify and solve subtraction problems
Why this, why now
In this unit pupils will explain how increasing or decreasing the minuend affects the difference and solve subtraction calculations mentally by using known facts explaining how adjusting the minuend can make mental calculation easier.
Prior knowledge requirements
- Ardaydu waa inay yaqaanaan aasaaska maadada.
- Ardaydu waa inay awoodaan inay raacaan tilmaamo fudud.
Unit 3 / 21
Use equivalence and compensation to simplify and solve subtraction problems
In this unit pupils will explain how increasing or decreasing the minuend affects the difference and solve subtraction calculations mentally by using known facts explaining how adjusting the minuend can make mental calculation easier.
10 lessons- Explain and represent constant difference for subtraction
- Use equivalence and compensation strategies to solve subtraction problems in a range of contexts
- Calculate the difference using knowledge of an adjusted subtrahend: difference structure
- Solve subtraction calculations mentally by using known facts
- Explain how adjusting the subtrahend affects the difference: reduction structure
- Explain how constant difference can make written calculations more efficient
- Explain how increasing or decreasing the minuend affects the difference
- Explain how adjusting the minuend can make mental calculation easier
- Use constant difference to balance equations and find unknowns
- Explain how adjusting the subtrahend affects the difference: partitioning