Lesson 6

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 \(8 ^\circ \text{F}\).

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?

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

Match the statements written in English with the mathematical statements. All of these statements are true.

Evaluate each expression.

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