Basic Mathematics for College Students

Adding two integers that have different (unlike)

signs

To add a positive integer and a negative integer,

subtract the smaller absolute value from the larger.

1.If the positive integer has the larger absolute

value, the final answer is positive.

2.If the negative integer has the larger absolute

value, make the final answer negative.

Add:

Find the absolute values: and.

Subtract the smaller absolute value from the larger:

12  7 5. Since the positive number, 12, has the

larger absolute value, the final answer is positive.

Add:

Find the absolute values: and.

Subtract the smaller absolute value from the larger:

8  3 5. Since the negative number, 8, has the

larger absolute value, make the final answer negative.

 8  3  5

0  80  8 030  3

 8  3

 7  12  5

0  70  7 0120  12

 7  12

194 Chapter 2 The Integers

'80

–150

–100

–50

50

0

100

250

$ billions

–250

–200

–350

Federal Budget Deficit/Surplus

(Office of Management and Budget)

'85 '90 '95 '05

'00

–300

'07

–250

–300

–450

–400

150

200

(Source: U.S. Bureau of the Census)

Position Player Score to Par

1 2 3 4 5 6

Source: golf.fanhouse.com

10. Explain the meaning of each red symbol.
    a.
    b.
    c.
    d.


11. LADIES PROFESSIONAL GOLF ASSOCIATION
    The scores of the top six finishers of the 2008 Grand
    China Air LPGA Tournament and their final scores
    related to par were: Helen Alfredsson , Laura
    Diaz , Shanshan Feng , Young Kim ,
    Karen Stupples , and Yani Tseng.
    Complete the table below. Remember, in golf, the
    lowest score wins.

(7) (9)

(8) (5) (6)

(12)

5 (5)

(5)

(5)

 5

 12. FEDERAL BUDGET The graph shows the U.S.

government’s deficit/surplus budget data for the

years 1980–2007.

a. When did the first budget surplus occur?

Estimate it.

b. In what year was there the largest surplus?

Estimate it.

c. In what year was there the greatest deficit?

Estimate it.

SECTION 2.2 Adding Integers

Adding two integers that have the same (like) signs

1.To add two positive integers, add them as usual.

The final answer is positive.

2.To add two negative integers, add their absolute

values and make the final answer negative.

DEFINITIONS AND CONCEPTS EXAMPLES

Add:

Find the absolute values: and.

Add their absolute values, 5 and 10, to get 15.

Then make the final answer negative.

 5 (10) 15

0  50  5 0  100  10

 5 (10)