Lesson 2

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?

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 \(8 ^\circ \text{F}\).

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.  _____ > \(\text- 2^\circ \text{C}\)

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

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?