5.6.2 Self-Check on Negative Numbers

Exercise symbol Exercise 3: Cold Temperatures

Write down the temperatures that are described in the following situations.

(a) The temperature was 3 °C during the day, but it fell by seven degrees Celsius overnight. What was the minimum temperature during the night?

Solution symbol

Answer

As equation left hand side three minus seven equals right hand side four minus, the minimum temperature was –4 °C.

(b) In Moscow, the temperature outside was six degrees Celsius colder than the freezer. If the freezer temperature was 18 °C, what was the outside temperature?

Solution symbol

Answer

As equation left hand side one minus times eight minus six equals right hand side two minus times four, the outside temperature in Moscow was 24 °C.

(c) The temperature outside is 5 °C. If it rises by seven degrees Celsius what is the new temperature?

Solution symbol

Answer

As five minus plus seven equals two, the new temperature is 2 °C.

Exercise symbol Exercise 4: Mt. Everest versus the Dead Sea

Mt. Everest, the highest elevation on Earth, is 29,028 feet above sea level. The shore of the Dead Sea is 1,312 feet below sea level, the lowest point on land. What is the difference between these extreme points on Earth?

Solution symbol

Answer

The difference between extremes is 29 comma 028 feet negative open one minus comma 312 feet close equals 29 comma 028 feet prefix plus of one comma 312 feet equals 30 comma 340 feet.

Exercise symbol Exercise 5: Yellow Submarine

A submarine was situated 450 feet below sea level. If it descends 300 feet, what is its new position?

Solution symbol

Answer

The submarine is now located at open four minus times 50 close feet negative 300 feet equation left hand side equals right hand side open seven minus times 50 close feet or 750 feet below sea level.

Exercise symbol Exercise 6: Battle of the Deserts

In the Sahara Desert, during the day, it was 136 °F. In the Gobi Desert, at night, a temperature of 50 °F was recorded. What is the difference between these two temperatures?

Solution symbol

Answer

The temperature difference is 136 degree cap f negative open five minus times zero degree cap f close equals 136 degree cap f prefix plus of 50 degree cap f equals 186 degree cap f.

5.6.1 Self-Check on Units of Measurement

5.6.3 Self-Check on Multiplication and Division of Negative Numbers