Chapter 5.1B, Problem 10A

ASSESSMENT

In each of the following problems, write an addition or subtraction statement and then solve the problem.

a. The hottest temperature ever recorded in the state of Arizona, ${128}^{\circ }F$, occurred on June 29, 1994, at lake Havasu. The lowest temperature in the state, $40^{\circ }F$, was recorded at Hawley Lake on January 7, 1971. What was the difference between hottest and lowest temperatures?

b. Barbara made a cup of coffee with a temperature of ${90}^{\circ }F$. She left it to cool, but forgot about it for $20$ minutes, and its temperature dropped by ${74}^{\circ }F$. She reheated her coffee in the microwave, which increased its temperature by ${58}^{\circ }F$, and then she drank it. How hot was her coffee at the point of drinking?

c. At $4$ P.M., the temperature in Barcelona was ${28}^{\circ }F$. By $2$ A.M., it had dropped by ${15}^{\circ }F$, but by $10$ A.M. the following morning it had risen by ${11}^{\circ }F$. What was the temperature in Barcelona at $10$ A.M.?

d. If it is $26^{\circ }F$ in Iceland and ${104}^{\circ }F$ in Australia, what is the difference in temperatures?