Question

Christopher spends a winter day recording the temperature once every three hoursfor science class. At 9 am, the temperature was -10.3°F. Between 9am and noon, thetemperature rose 9.6°F. Between noon and 3pm, the temperature went up 15.8°F.Between 3pm and 6pm, the temperature went down 14.2°F. What was thetemperature at 6pm?

Answer 1

1) The temperature at 9 a.m. was -10.3ºF, this is the initial temperature of the trial.

2) Between 9 a.m. and noon the temperature rose 9.6ºF, to determine what was the temperature at noon, you have to add 9.6ºF to the initial temperature:

$-10.3+9.6=-0.7ºF$

The temperature at noon was -0.7ºF

3) Between noon and 3 p.m. the temperature went up 15.8ºF

To determine what was the temperature at 3 p.m. you have to add 15.8ºF to the temperature obtained in step 2

$-0.7+15.8=15.1ºF$

The temperature at 3 p.m. was 15.1ºF

4) Between 3 p.m. and 6 p.m. the temperature went down by 14.2ºF. To determine the temperature at 6 p.m., since the temperature decreased, you have to subtract 14.2ºF from 15.1ºF

$15.1-14.2=0.9ºF$

The temperature at 6 p.m. was 0.9ºF