A number line can represent positions that are north and south of a truck stop on a highway. Decide whether you want positive positions to be north or south of the truck stop. Then plot the following positions on a number line.

1. The truck stop
2. 5 miles north of the truck stop

3. 3.5 miles south of the truck stop

1. How could you distinguish between traveling west at 5 miles per hour and traveling east at 5 miles per hour without using the words “east” and “west”?
2. Four people are cycling. They each start at the same point. (0 represents their starting point.) Plot their finish points after 5 seconds of cycling on a number line.

A weather station on the top of a mountain reports that the temperature is currently \(0^\circ\text{C}\) and has been falling at a constant rate of \(3^\circ\text{C}\) per hour. If it continues to fall at this rate, find each indicated temperature. Explain or show your reasoning.

1. What will the temperature be in 2 hours?

2. What will the temperature be in 5 hours?

3. What will the temperature be in \(\frac12\) hour?

4. What was the temperature 1 hour ago?

5. What was the temperature 3 hours ago?

6. What was the temperature 4.5 hours ago?

Find the value of each expression.

1. \(16.2 + \text-8.4\)
2. \(\frac25 - \frac35\)
3. \(\text-9.2 + \text-7\)
4. \(\text-4\frac38 - (\text-1\frac14)\)