Lesson 2

Changing Temperatures

The practice problem answers are available at one of our IM Certified Partners

Problem 1

  1. The temperature is -2\(^\circ \text{C}\). If the temperature rises by 15\(^\circ \text{C}\), what is the new temperature?
  2. At midnight the temperature is -6\(^\circ \text{C}\). At midday the temperature is 9\(^\circ \text{C}\). By how much did the temperature rise?

Problem 2

Draw a diagram to represent each of these situations. Then write an addition expression that represents the final temperature.

  1. The temperature was \(80 ^\circ \text{F}\) and then fell \(20 ^\circ \text{F}\).
  2. The temperature was \(\text-13 ^\circ \text{F}\) and then rose \(9 ^\circ \text{F}\).
  3. The temperature was \(\text-5 ^\circ \text{F}\) and then fell \(8 ^\circ \text{F}\).

Problem 3

Complete each statement with a number that makes the statement true.

  1.  _____ < \(7^\circ \text{C}\)
  2.  _____ < \(\text- 3^\circ \text{C}\)
  3.  \(\text- 0.8^\circ \text{C}\) < _____ < \(\text- 0.1^\circ \text{C}\)
  4.  _____ > \(\text- 2^\circ \text{C}\)
(From Grade7, Unit 5, Lesson 1.)

Problem 4

Decide whether each table could represent a proportional relationship. If the relationship could be proportional, what would be the constant of proportionality?

  1. The number of wheels on a group of buses.

    number of buses number of wheels wheels per bus
    5 30
    8 48
    10 60
    15 90
  2. The number of wheels on a train.

    number of train cars number of wheels wheels per train car
    20 184
    30 264
    40 344
    50 424
(From Grade7, Unit 2, Lesson 7.)

Problem 5

Noah was assigned to make 64 cookies for the bake sale. He made 125% of that number. 90% of the cookies he made were sold. How many of Noah's cookies were left after the bake sale?

(From Grade7, Unit 4, Lesson 7.)