Exercises: Decimals (1.5)

Exercises: Name and Write Decimals

Instructions: For questions 1–8, write as a decimal.

1. Twenty-nine and eighty-one hundredths

Solution

$29.81$

2. Sixty-one and seventy-four hundredths

3. Seven tenths

Solution

$0.7$

4. Six tenths

5. Twenty-nine thousandth

Solution

$0.029$

6. Thirty-five thousandths

7. Negative eleven and nine ten-thousandths

Solution

$-11.0009$

8. Negative fifty-nine and two ten-thousandths

Exercises: Name and Write Decimals

Instructions: For questions 9–16, name each decimal.

9. $5.5$

Solution

five and five tenths

10. $14.02$

11. $8.71$

Solution

eight and seventy-one hundredths

12. $2.64$

13. 0.002

Solution

two thousandths

14. 0.479

15. $−17.9$

Solution

negative seventeen and nine tenths

16. $-31.4$

Exercises: Round Decimals

Instructions: For questions 17–20, round each number to the nearest tenth.

17. $0.67$

Solution

$0.7$

18. $0.49$

19. $2.84$

Solution

$2.8$

20. $4.63$

Exercises: Round Decimals

Instructions: For questions 21–26, round each number to the nearest hundredth.

21. $0.845$

Solution

$0.85$

22. $0.761$

23. $0.299$

Solution

$0.30$

24. $0.697$

25. $4.098$

Solution

$4.10$

26. $7.096$

Exercises: Round Decimals

Instructions: For questions 27–30, round each number to the nearest

a. hundredth
b. tenth
c. whole number

27. $5.781$

Solution

a. $5.78$
b. $5.8$
c. $6$

28. $1.6381$

29. $63.479$

Solution

a. $63.48$
b. $63.5$
c. $63$

30. $84.281$

Instructions: For questions 31–48, add or subtract.

31. $16.92+7.56$

Solution

$24.48$

32. $248.25-91.29$

33. $21.76-30.99$

Solution

$-9.23$

34. $38.6+13.67$

35. $-16.53-24.38$

Solution

$-40.91$

36. $-19.47-32.58$

37. $-38.69+31.47$

Solution

$-7.22$

38. $29.83+19.76$

39. $72.5-100$

Solution

$-27.5$

40. $86.2-100$

41. $15+0.73$

Solution

$15.73$

42. $27+0.87$

43. $91.95-(-10.462)$

Solution

$102.212$

44. $94.69-(-12.678)$

45. $55.01-3.7$

Solution

$51.31$

46. $59.08-4.6$

47. $2.51-7.4$

Solution

$-4.89$

48. $3.84-6.1$

Exercises: Multiply and Divide Decimals

Instructions: For questions 49–62, multiply.

49. $(0.24)(0.6)$

Solution

$0.144$

50. $(0.81)(0.3)$

51. $(5.9)(7.12)$

Solution

$42.008$

52. $(2.3)(9.41)$

53. $(-4.3)(2.71)$

Solution

$-11.653$

54. $(-8.5)(1.69)$

55. $(-5.18)(-65.23)$

Solution

$337.8914$

56. $(-9.16)(-68.34)$

57. $(0.06)(21.75)$

Solution

$1.305$

58. $(0.08)(52.45)$

59. $(9.24)(10)$

Solution

$92.4$

60. $(6.531)(10)$

61. $(55.2)(1000)$

Solution

$55\text{,}200$

62. $(99.4)(1000)$

Exercises: Multiply and Divide Decimals

Instructions: For questions 63–76, divide.

63. $4.75\div25$

Solution

$0.19$

64. $12.04\div43$

65. $117.25\div48$

Solution

$2.44$

66. $109.24\div36$

67. $0.6\div0.2$

Solution

$3$

68. $0.8\div0.4$

69. $1.44\div(-0.3)$

Solution

$-4.8$

70. $1.25\div(-0.5)$

71. $-1.75\div(-0.05)$

Solution

$35$

72. $-1.15\div(-0.05)$

73. $5.2\div2.5$

Solution

$2.08$

74. $6.5\div3.25$

75. $11\div0.55$

Solution

$20$

76. $14\div0.35$

Exercises: Convert Decimals, Fractions and Percents

Instructions: For questions 77–98, write each decimal as a fraction.

77. $0.04$

Solution

$\frac{1}{25}$

78. $0.19$

79 .$0.52$

Solution

$\frac{13}{25}$

80. $0.78$

81. $1.25$

Solution

$\frac{5}{4}$

82. $1.35$

83. $0.375$

Solution

$\frac{3}{8}$

84. $0.464$

85. $0.095$

Solution

$\frac{19}{200}$

86. $0.085$

Exercises: Convert Decimals, Fractions and Percents

Instructions: For questions 87-98, convert each fraction to a decimal.

87. $\frac{17}{20}$

Solution

$0.85$

88. $\frac{13}{20}$

89. $\frac{11}{4}$

Solution

$2.75$

90. $\frac{17}{4}$

91. $-\frac{310}{25}$

Solution

$-12.4$

92. $-\frac{284}{25}$

93. $\frac{15}{11}$

Solution

$1.\overline{36}$

94. $\frac{18}{11}$

95. $\frac{15}{111}$

Solution

$0.\overline{135}$

96. $\frac{25}{111}$

97. $2.4+\frac{5}{8}$

Solution

$3.025$

98. $3.9+\frac{9}{20}$

Exercises: Convert Decimals, Fractions and Percents

Instructions: For questions 99–108, convert each percent to a decimal.

99. $1\%$

Solution

$0.01$

100. $2\%$

101. $63\%$

Solution

$0.63$

102. $71\%$

203. $150\%$

Solution

$1.5$

104. $250\%$

105. $21.4\%$

Solution

$0.214$

106. $39.3\%$

107. $7.8\%$

Solution

$0.078$

108. $6.4\%$

Exercises: Convert Decimals, Fractions and Percents

Instructions: For questions 109–118, convert each decimal to a percent.

109. $0.01$

Solution

$1\%$

110. $0.03$

111. $1.35$

Solution

$135\%$

112. $1.56$

113. $3$

Solution

$300\%$

114. $4$

115. $0.0875$

Solution

$8.75\%$

116. $0.0625$

117. $2.254$

Solution

$225.4\%$

118. $2.317$

Exercises: Everyday Math

Instructions: For questions 119–124, answer the given everyday math word problems.

119. Salary Increase. Danny got a raise and now makes $58\text{,}965.95$ a year. Round this number to the nearest

a. dollar
b. thousand dollars
c. ten thousand dollars

Solution

a. $58\text{,}966$
b. $59\text{,}000$
c. $60\text{,}000$

120. New Car Purchase. Selena’s new car cost $23\text{,}795.95$. Round this number to the nearest

a. dollar
b. thousand dollars
c. ten thousand dollars

121. Sales Tax. Hyo Jin lives in San Diego. She bought a refrigerator for $1\text{,}624.99$ and when the clerk calculated the sales tax it came out to exactly $142.186625$. Round the sales tax to the nearest

a. penny
b. dollar

Solution

a. $142.19$
b. $142$

122. Sales Tax. Jennifer bought a $1\text{,}038.99$ dining room set for her home in Cincinnati. She calculated the sales tax to be exactly $67.53435$. Round the sales tax to the nearest

a. penny
b. dollar

123. Paycheck. Annie has two jobs. She gets paid $14.04$ per hour for tutoring at City College and $8.75$ per hour at a coffee shop. Last week she tutored for 8 hours and worked at the coffee shop for 15 hours.

a. How much did she earn?
b. If she had worked all 23 hours as a tutor instead of working both jobs, how much more would she have earned?

Solution

a. $243.57$
b. $79.35$

124. Paycheck. Jake has two jobs. He gets paid $7.95$ per hour at the college cafeteria and $20.25$ at the art gallery. Last week he worked 12 hours at the cafeteria and 5 hours at the art gallery.

a. How much did he earn?
b. If he had worked all 17 hours at the art gallery instead of working both jobs, how much more would he have earned?

Exercises: Writing Exercises

Instructions: For questions 119–124, answer the given writing exercises.

Solution

126. Explain how you write “three and nine hundredths” as a decimal.

127. Without solving the problem “$44$ is $80\%$ of what number” think about what the solution might be. Should it be a number that is greater than $44$ or less than $44$? Explain your reasoning.

Solution

128. When the Szetos sold their home, the selling price was $500\%$ of what they had paid for the house 30 years ago. Explain what $500\%$ means in this context.