# Lesson 10

Subtracting Rational Numbers

### Problem 1

Write a sentence to answer each question:

1. How much warmer is 82 than 40?

2. How much warmer is 82 than -40?

### Problem 2

1. What is the difference in height between 30 m up a cliff and 87 m up a cliff? What is the distance between these positions?

2. What is the difference in height between an albatross flying at 100 m above the surface of the ocean and a shark swimming 30 m below the surface? What is the distance between them if the shark is right below the albatross?

### Problem 3

The table shows four transactions and the resulting account balance in a bank account, except some numbers are missing. Fill in the missing numbers.

transaction amount account balance
transaction 1 360 360
transaction 2 -22.50 337.50
transaction 3 182.35
transaction 4 -41.40

### Problem 4

Find each difference.

• $$(\text-5) - 6$$

• $$35 - (\text-8)$$

• $$\frac25 - \frac35$$

• $$\text-4\frac38 - (\text-1\frac14)$$

### Problem 5

Last week, it rained $$g$$ inches. This week, the amount of rain decreased by 5%. Which expressions represent the amount of rain that fell this week? Select all that apply.

A:

$$g - 0.05$$

B:

$$g - 0.05g$$

C:

$$0.95g$$

D:

$$0.05g$$

E:

$$(1-0.05)g$$

### Solution

(From Unit 6, Lesson 5.)

### Problem 6

A company produces screens of different sizes. Based on the table, could there be a relationship between the number of pixels and the area of the screen? If so, write an equation representing the relationship. If not, explain your reasoning.

square inches of screen number of pixels
6 31,104
72 373,248
105 544,320
300 1,555,200