Killian is using integer tiles to add 7+(−2)

Question

In which step did Jillian make a mistake? Explain in your own words how to correct Jillian's work and what the correct answer is.



NOTE: To receive full credit on this question, you must do three things:

1. State the step in which Jillian made a mistake.

2. Explain how to correct Jillian's work.

3. State the correct final answer.

Answer 1

1. Step in which Jillian made a mistake: Jillian likely made an error in the addition step when combining the numbers 7 and -2. She may have miscalculated or misinterpreted the operation as simply adding the two values rather than recognizing that adding a negative number is equivalent to subtracting.

2. How to correct Jillian's work: To correct Jillian's work, we should clarify that when you add a negative number, it's the same as subtracting the positive equivalent of that number. In this case, instead of adding 7 and -2 together, you should perform the operation as \(7 + (-2)\) which can be rewritten as \(7 - 2\). This means you start with 7 and then move 2 units to the left on the number line, leading to the correct calculation.

3. The correct final answer: The correct calculation yields \(7 - 2 = 5\). Therefore, the final answer is 5.