Question

Ben is showing his work in simplifying (3.9 − 9.4) − 0.6 + 6.1. Identify any error in his work or reasoning.

Step 1: (3.9 − 9.4) − 0.6 + 6.1
Step 2: 3.9 + (− 9.4 − 0.6) + 6.1 (associative property)
Step 3: 3.9 − 10 + 6.1
Step 4: 3.9 + 6.1 − 10 (identity property)
Step 5: 10 − 10 = 0

He wrote identity instead of commutative in Step 4.

He wrote associative instead of commutative in Step 2.

He wrote identity instead of distributive in Step 4.

He wrote associative instead of distributive in Step 2.