On Monday, the temp was 14 degrees Celsius. On Tuesday, it dropped 5 degrees. On Wednesday, it dropped another 10 degrees. On Thursday, it increased 8 degrees. On the end of the day on Thursday, the temperature was 7 degrees Celsius.
14 - 5 - 10 + 8 = 7.
Temperatures for each day:
Monday: 14 degrees.
Tuesday: 9 degrees.
Wednesday: -1 degrees.
Thursday: 7 degrees.