Use equivalence and compensation to simplify and solve subtraction problems

Explain and represent constant difference for subtraction

Explain how constant difference can make written calculations more efficient

Use constant difference to balance equations and find unknowns

Explain how increasing or decreasing the minuend affects the difference

Solve subtraction calculations mentally by using known facts

Explain how adjusting the minuend can make mental calculation easier

Explain how adjusting the subtrahend affects the difference: reduction structure

Explain how adjusting the subtrahend affects the difference: partitioning

Calculate the difference using knowledge of an adjusted subtrahend: difference structure

Use equivalence and compensation strategies to solve subtraction problems in a range of contexts