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Apply the associative, commutative and distributive laws to aid mental and written computation (ACMNA151)

Source: Australian Curriculum, Assessment and Reporting Authority (ACARA)

The commutative and associative rules apply to addition.

In general if a and b are numbers

a + b = b + a  (commutative law for addition)

For example, 7 + 8 = 8 + 7

(a + b) + c = a + (b + c)  (associative law for addition)

For example, (7 + 5) + 6 = 7 + (5 + 6)

It is not necessary for students to use the names of the laws or identify when a rule is being employed. Students should be aware of the properties and use them for mental and written computation.

They are also important in algebra.