Basic Mathematics for College Students

Chapter 4 Summary and Review 397

Name GPA

Diaz, Cielo 3.9809

Chou, Wendy 3.9808

Washington, Shelly 3.9865

Gerbac, Lance 3.899

Singh, Amani 3.9713

SECTION 4.2 Adding and Subtracting Decimals

To add or subtract decimals:

1.Write the numbers in vertical formwith the

decimal points lined up.

2.Add (or subtract) as you would whole numbers.

3.Write the decimal point in the result from

Step 2 below the decimal points in the problem.

If the number of decimal places in the problem are

different, insert additional zeros so that the

number of decimal places match.

DEFINITIONS AND CONCEPTS EXAMPLES

28. ALLERGY FORECAST The graph below shows a
    four-day forecast of pollen levels for Las Vegas,
    Nevada. Determine the decimal-number forecast for
    each day.
    Allergy Alert 4-Day Forecast
    for Las Vegas, Nevada

1.0

2.0

Sun.

3.0

4.0

Mon. Tues. Wed.

Write each decimal in words and then as a fraction or mixed

number.

4. 2.3


5. –615.59


6. 0.0601


7. 0.00001
   Write each number in standard form.


8. One hundred and sixty-one hundredths


9. 0.2222282 nearest millionth


10. 0.635265 nearest hundred-thousandth
    Round each given dollar amount.


11. $0.671456 to the nearest cent


12. $12.82 to the nearest dollar


13. VALEDICTORIANS At the end of the school
    year, the five students listed below were in the
    running to be class valedictorian (the student with
    the highest grade point average). Rank the students
    in order by GPA, beginning with the valedictorian.

Add:

Write the problem in vertical form and add, column-by-column,

working right to left.

Line up the decimal points.

To checkthe result, add bottom to top.

Insert an extra zero.

Insert a decimal point and extra zeros.

1

1

5

1

.8

1

20

19 .000

 32.995

67.815

15.82 19 32.995



9. Eleven and nine hundred ninety-seven thousandths


10. Three hundred one and sixteen millionths
    Place an or an symbol in the box to make a true statement.


11. 5.68 5.75


12. 106.8199 106.82


13. 
    


14. 
    


15. Graph: 1.55, , , and.


16. Determine whether each statement is true or false.
    a. b.
    c. d.
    Round each decimal to the indicated place value.


17. 4.578 nearest hundredth


18. 3,706.0815 nearest thousandth


19. nearest tenth


20. nearest tenth


21. 6.702983 nearest ten-thousandth


22. 11.314964 nearest ten-thousandth

88.12

0.0614

3.47003.470 0.008.00800

78 78.0 6.9106.901

–5 –4–3–2 –1 0 1 2 3 4 5

0.82.1 2.7

555.098 555.0991

78.23 78.303