# Lesson 10

Multiply!

### Problem 1

Evaluate each expression:

1. $$\text-12 \boldcdot \frac13$$
2. $$\text-12 \boldcdot \text{-}\frac {1}{3}$$
3. $$12 \boldcdot \left(\text{-}\frac {5}{4}\right)$$
4. $$\text-12 \boldcdot \left(\text{-}\frac {5}{4}\right)$$

### Problem 2

Evaluate each expression:

1. $$\text-1 \boldcdot 2 \boldcdot 3$$
2. $$\text-1 \boldcdot (\text-2) \boldcdot 3$$
3. $$\text-1 \boldcdot (\text-2) \boldcdot (\text-3)$$

### Problem 3

Order each set of numbers from least to greatest.

1. 4, 8, -2, -6, 0
2. -5, -5.2, 5.5, $$\text-5\frac12$$, $$\frac {\text{-}5}{2}$$

### Solution

(From Unit 5, Lesson 1.)

### Problem 4

$$30 + \text-30 = 0$$.

1. Write another sum of two numbers that equals 0.
2. Write a sum of three numbers that equals 0.
3. Write a sum of four numbers that equals 0, none of which are opposites.

### Solution

(From Unit 5, Lesson 3.)

### Problem 5

A submarine is searching for underwater features. It is accompanied by a small aircraft and an underwater robotic vehicle.

At one time the aircraft is 200 m above the surface, the submarine is 55 m below the surface, and the underwater robotic vehicle is 227 m below the surface.

1. What is the difference in height between the submarine and the aircraft?
2. What is the distance between the underwater robotic vehicle and the submarine?

### Solution

(From Unit 5, Lesson 6.)

### Problem 6

1. Clare is cycling at a speed of 12 miles per hour. If she starts at a position chosen as zero, what will her position be after 45 minutes?
2. Han is cycling at a speed of -8 miles per hour; if he starts at the same zero point, what will his position be after 45 minutes?
3. What will the distance between them be after 45 minutes?

### Solution

(From Unit 5, Lesson 8.)

### Problem 7

Fill in the missing numbers in these equations

1. $$(\text-7)\boldcdot {?} = \text-14$$
2. $${?}\boldcdot 3 = \text-15$$
3. $${?}\boldcdot 4 = 32$$
4. $$\text-49 \boldcdot 3 ={?}$$