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)

(1 point)
Responses

Sebastian should have used –5 and 8.
Sebastian should have used –5 and 8.

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

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
.

Answer 1

In the scenario described, Sebastian initially goes up 8 floors and then down 5 floors. To represent this mathematically, we can think of his movements in terms of starting from a point (let's say ground level or 0) where moving up is positive and moving down is negative.

1. Up 8 floors can be represented as +8.
2. Down 5 floors can be represented as -5.

The total change in position can be represented by adding these two movements together:

\[ 0 + 8 - 5 \]

This simplifies to:

\[ 8 - 5 = 3 \]

So he ends up 3 floors above the ground.

However, the expression you provided, \( 5 + (-8) \), is not a correct representation of his movements since it suggests that he starts at 5 and then goes down 8, which doesn't fit the scenario.

Among the options provided:

- **Sebastian should have used –5 and 8.** (Incorrect)
- **Sebastian should have started at zero before adding –8.** (Incorrect)
- **Sebastian should have used 0 and –8.** (Incorrect)
- **Sebastian should have switched the two addends and written −8 + 5.** (Correct way to express movement)

The most accurate response is: **Sebastian should have switched the two addends and written -8 + 5.**