Lesson 8 Solve Problems with Rational Numbers

To determine your answer, think about distance on a number line and whether the temperature is going up or down.

• -20 degrees

• -4 degrees

• 4 degrees

• 20 degrees

Remember to use order of operations!

• 13.8

• 5.52

• -5.52

• -13.8

• -3.32

• -1.66

• -7.20

• 3 ¾

• 6 ⅔

• 7 ½

• Antoine is about 17 years older than Katy.

• Antoine is about 6 years older than Katy.

• Antoine is about 6 years younger than Katy.

• Antoine is about 17 years younger than Katy.

A scientist measures the change in the temperature of a chemical solution. At the start of the experiment, the solution is at a temperature of -14.96 $\degree$ C.  The temperature decreases 2.9 $\degree$ C each hour.
Which expression that can be used to find the temperature of the solution after 3 hours?

• -14.96 - (2.9 $\cdot$  3)

• -14.96  + 2.9 $\cdot$  3

• (-14.96 - 2.9)  $\cdot$  3

• (-14.96 + 2.9)  $\div$  3

A scientist measures the change in the temperature of a chemical solution. At the start of the experiment, the solution is at a temperature of -14.96 $\degree$  C.  The temperature decreases 2.9 $\degree$  C each hour.
What is the temperature of the solution after 3 hours, rounded to the nearest whole degree?  Estimate to check that your answer is reasonable.

• -6

• -54

• -24

• -4

Amelia is scuba diving at a position 24.25 feet below sea level. She descends 0.5 foot each minute for 25 minutes. What is Amelia's position compared to sea level after 25 minutes? (Remember that Amelia is starting at 24.25 ft below sea level)

• -24.75 feet

• 24.75 feet

• -36.75 feet

• 36.75 feet