Final answer:
The temperature increased by 5 degrees from 9 pm to 11 pm, going from -6 degrees to -1 degree. This was determined by subtracting the initial temperature from the final temperature while considering the rules of negative numbers.
Step-by-step explanation:
The change of temperature from 9 pm to 11 pm is found by subtracting the initial temperature from the final temperature. In this case, the temperature changed from -6 degrees at 9 pm to -1 degrees at 11 pm.
To find the amount of change, we take the later temperature and subtract the earlier temperature: -1 degrees (at 11 pm) - (-6 degrees) (at 9 pm). Performing this calculation, we get -1 - (-6) = -1 + 6 = 5 degrees.
Therefore, the temperature increased by 5 degrees from 9 pm to 11 pm. It's important to note that higher negative temperatures are actually warmer than lower negative temperatures, which sometimes can be a bit tricky to understand.