Basic Mathematics for College Students

152 Chapter 2 The Integers

1. a. b. c. 2. 3. a. 5 b. c. 382 4. 5. 6.


2. 6 8.50°F

 9  73  494  3  14  9  9  5

ANSWERS TO SELF CHECKS

VOCABULARY

Fill in the blanks.

1. Two negative integers, as well as two positive integers,
   are said to have the same or signs.


2. A positive integer and a negative integer are said to
   have different or signs.


3. When 0 is added to a number, the number remains
   the same. We call 0 the additive.


4. Since , we say that 5 is the additive
   of. We can also say that 5 and are.


5. property of addition: The order in
   which integers are added does not change their sum.


6. property of addition: The way in which
   integers are grouped does not change their sum.

CONCEPTS

7. a.What is the absolute value of 10? What is the
   absolute value of  12?

 5  5

 5  5  0

b. Which number has the larger absolute value,

10 or?

c. Using your answers to part a, subtract the smaller

absolute value from the larger absolute value.

What is the result?

8. a.If you lost $6 and then lost $8, overall, what
   amount of money was lost?
   b. If you lost $6 and then won $8, overall, what
   amount of money have you won?

Fill in the blanks.

9. To add two integers with unlike signs, their
   absolute values, the smaller from the larger. Then
   attach to that result the sign of the number with the
   absolute value.


10. To add two integers with like signs, add their
    values and attach their common
    to the sum.

 12

SECTION 2.2 STUDY SET

Using Your CALCULATOR Entering Negative Numbers

Canada is the largest U.S. trading partner. To calculate the

2007 U.S. trade balance with Canada, we add the $249

billion worth of U.S. exports toCanada (considered positive)

to the $317 billion worth of U.S. imports fromCanada (considered negative).

We can use a calculator to perform the addition:

We do not have to do anything special to enter a positive number. Negative

numbers are entered using either director reverse entry,depending on the

type of calculator you have.

To enter 317 using reverse entry, press the change-of-sign key after

entering317. To enter 317 using direct entry, press the negative key

beforeentering 317. In either case, note that and the keys are

different from the subtraction key.

Reverse entry: 249 317

Direct entry: 249 317

In 2007, the United States had a trade balance of billion with Canada.

Because the result is negative, it is called a trade deficit.

$68

 () ENTER ^68

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/ ()

()

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249 (317)