Ask a New Question
Menu

Question

Sebastian was in a hotel lobby and took the elevator up 8 floors to his room. Then he took the elevator down 5 floors to the parking garage. He described his movement with the expression below.

5+(−8)



NOTE: There is a check answer button in the bottom right corner. Click this to check your answer before moving on to the next question. It will not tell you the correct answer, but it will tell you if the answer you selected is correct. You can use this feature twice per question.

(1 point)
Responses

Sebastian should have used 0 and –8.
Sebastian should have used 0 and –8.

Sebastian should have switched the two addends and written −8+5
.
Sebastian should have switched the two addends and written negative 8 plus 5.

Sebastian should have started at zero before adding –8.
Sebastian should have started at zero before adding –8.

Sebastian should have used –5 and 8.

1 answer

To analyze Sebastian's movements:

  1. He took the elevator up 8 floors to his room, which can be represented as +8.
  2. Then, he took the elevator down 5 floors to the parking garage, which can be represented as -5.

The expression that accurately represents Sebastian's movement should start from a baseline (like 0) and then account for his up and down movements:

  • Starting at 0, he goes up 8 floors: 0 + 8 = 8 (his room).
  • Then, he goes down 5 floors: 8 - 5 = 3 (parking garage).

Thus, the movements can be represented as 0 + 8 + (-5), which simplifies to 8 - 5 = 3.

From the options provided:

  1. "Sebastian should have used 0 and -8." (incorrect)
  2. "Sebastian should have switched the two addends and written −8+5." (incorrect)
  3. "Sebastian should have started at zero before adding –8." (misleading, since he went up first)
  4. "Sebastian should have used –5 and 8." (this represents his down movement first, which isn't how he described it)

Considering the above analysis, none of the responses perfectly describe the mathematical representation of Sebastian's movement. However, the closest correct approach to solve his movements would be starting from 0 before moving:

The correct interpretation as per the expression would be "Sebastian should have started at zero and used +8, -5."

However, since that option does not exist, the most correct is: Sebastian should have started at zero before adding –8.

But note that it doesn’t ideally represent his entire elevator ride. The actual movement should be accounted as +8 and -5 starting from 0.