If a student evaluated the expression (3 + 7) - 6/2 to equal 2 on an exam, what error did she most likely make?

When evaluating the expression (3 + 7) - 6/2, it is important to follow the order of operations, commonly remembered by the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)).

In this case, the correct steps to evaluate the expression are as follows:

1. Perform the operation inside the parentheses first: 3 + 7 equals 10.

2. Then evaluate the division: 6 divided by 2 equals 3.

3. Finally, perform the subtraction: 10 - 3 equals 7.

If the student disregarded the order and simply performed operations from left to right without considering the established hierarchy of operations, she may have first subtracted 6 from 3, yielding a negative result, and then continued performing operations without correctly applying the division step. This would lead to an incorrect final answer such as 2, demonstrating a misunderstanding of how to correctly apply order of operations.

Thus, the most likely error the student made aligns with performing operations from left to right without adhering to the appropriate sequence dictated by the order of operations.