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.

Question

5+(−8)


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(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.
Sebastian should have used –5 and 8.

Answer 1

To analyze Sebastian's movements, we can consider the starting point as the ground floor (which we can represent as 0).

1. Starting at the ground floor (0), he goes up 8 floors: This can be represented as +8.
2. Then he goes down 5 floors: This can be represented as -5.

Combining these movements, we can write the expression as:

0 + 8 - 5, which simplifies to 3.

Now, looking at the original expression described: 5 + (-8) does not accurately represent his movements, as it seems to imply starting at floor 5 and moving down 8 floors, which isn't the case.

Based on the analysis of movement:

• The correct representation would involve starting from 0 and using +8 for going up followed by -5 for going down.

Considering the options:

1. Sebastian should have used 0 and –8. - Incorrect.
2. Sebastian should have switched the two addends and written −8 + 5. - Incorrect order of movements.
3. Sebastian should have started at zero before adding –8. - This is a bit ambiguous since while he does start at zero, the expressions need to be correct, which they aren't.
4. Sebastian should have used –5 and 8. - As separate movements.

The closest correct answer is:

Sebastian should have started at zero before adding –8.

This effectively captures the idea of starting from zero and navigating through the floors, although it isn't the clearest.

However, based on the context, the most correct approach is that he should reflect his sequence of movements correctly in the equation. So, Sebastian should have used –5 and 8 would also convey that when considering the appropriate inputs into the equation representing his overall movement.

So, if you want to focus on alternative additions rather than direct sequencing, you may also lean towards:

Sebastian should have used –5 and 8.

I recommend selecting one of these two based on which aspect you'd like to emphasize.