1. Wednesday's lowest temperature was -18°C. The cold weather continued and by Friday, it had dropped another 9°C. What was the temperature on Friday?
2. The temperature at noon on a Monday in December was -11°C. By noon on Tuesday, it had
warmed by 17°C. What was the temperature at noon on Tuesday?
3. The top of a mountain has an altitude of 12,923 feet. The bottom of a valley is 195 feet below sea level. Find the difference between these two elevations.
4. Joe owed his mother $32. He gave her $23. Write his financial situation as a signed number.