Bradyn Wang

Mathematics

16 October, 12:55

Arlene is showing her work in simplifying - 7.9 + 8.2 - 3.4 + 2.1. Identify any errors in her work or in her reasoning. Write feedback to Arlene explaining the mistake she made and how to correct her work.

-7.9 + 8.2 - 3.4 + 2.1

(Original problem)

-7.9 + 8.2 + (-3.4) + 2.1

(Additive inverse)

-7.9 + (-3.4) + 8.2 + 2.1

(Associative property)

(-7.9 + (-3.4)) + (8.2 + 2.1) (Commutative property)

-11.3 + 10.3 (Simplify)

-1 (Simplify)