Question

Arlene us showing her work in simplifying(−7.9)+8.2−3.4+2.1 identify any error in her work or in her reasoning.

Answer 1

Keep doing each step manually, and see where it slips up: −7.9+8.2−3.4+2.1=−1 −7.9+8.2+(−3.4)+2.1=−1 −7.9+(−3.4)+8.2+2.1=−1 (−7.9+(−3.4))+(8.2+2.1)=−1 −11.3+10.3=−1