Question

A student made a mistake in the following problem 17 − (−3) and got an answer that was not correct. Identify the step in which the student made the mistake.

Step 1: 17 − (−3)

Step 2: 17 + (−3)

Step 3: 14

Answer 1

The mistake is in Step 2. They changed 17 − (−3) to 17 + (−3), which is wrong. Subtracting a negative is the same as adding the positive: 17 − (−3) = 17 + 3 = 20. Step 3 (14) follows from the incorrect Step 2.