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