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Name and Write Decimals
In the following exercises, write as a decimal.
Sixty-one and seventy-four hundredths
Six tenths
Thirty-five thousandths
Negative eleven and nine ten-thousandths
$\mathrm{-11.0009}$
Negative fifty-nine and two ten-thousandths
In the following exercises, name each decimal.
$\text{\u2212}17\text{.9}\phantom{\rule{0.2em}{0ex}}$
negative seventeen and nine tenths
$\text{\u2212}31\text{.4}$
Round Decimals
In the following exercises, round each number to the nearest tenth.
In the following exercises, round each number to the nearest hundredth.
In the following exercises, round each number to the nearest ⓐ hundredth ⓑ tenth ⓒ whole number.
$84\text{.281}\phantom{\rule{0.2em}{0ex}}$
Add and Subtract Decimals
In the following exercises, add or subtract.
$248.25-91.29$
$38.6+13.67$
$\mathrm{-19.47}-32.58$
$29.83+19.76$
$86.2-100$
$27+0.87$
$94.69-\left(\mathrm{-12.678}\right)$
$59.08-4.6$
$3.84-6.1$
Multiply and Divide Decimals
In the following exercises, multiply.
$\left(0.81\right)\left(0.3\right)$
$\left(2.3\right)\left(9.41\right)$
$\left(\mathrm{-4.3}\right)\left(2.71\right)$
$\mathrm{-11.653}$
$\left(\mathrm{-8.5}\right)\left(1.69\right)$
$\left(\mathrm{-5.18}\right)\left(\mathrm{-65.23}\right)$
337.8914
$\left(\mathrm{-9.16}\right)\left(\mathrm{-68.34}\right)$
$\left(0.08\right)\left(52.45\right)$
$\left(6.531\right)\left(10\right)$
$\left(99.4\right)\left(1000\right)$
In the following exercises, divide.
$12.04\xf743$
$\mathrm{\$109.24}\xf736$
$0.8\xf70.4$
$1.25\xf7\left(\mathrm{-0.5}\right)$
$\mathrm{-1.15}\xf7\left(\mathrm{-0.05}\right)$
$6.5\xf73.25$
$14\xf70.35$
Convert Decimals, Fractions and Percents
In the following exercises, write each decimal as a fraction.
In the following exercises, convert each fraction to a decimal.
$\frac{13}{20}$
$\frac{17}{4}$
$-\phantom{\rule{0.2em}{0ex}}\frac{310}{25}$
$\mathrm{-12.4}$
$-\phantom{\rule{0.2em}{0ex}}\frac{284}{25}$
$\frac{18}{11}$
$\frac{25}{111}$
$3.9+\frac{9}{20}$
In the following exercises, convert each percent to a decimal.
In the following exercises, convert each decimal to a percent.
Salary Increase Danny got a raise and now makes $58,965.95 a year. Round this number to the nearest
ⓐ dollar
ⓑ thousand dollars
ⓒ ten thousand dollars.
ⓐ $58,966 ⓑ $59,000 ⓒ $60,000
New Car Purchase Selena’s new car cost $23,795.95. Round this number to the nearest
ⓐ dollar
ⓑ thousand dollars
ⓒ ten thousand dollars.
Sales Tax Hyo Jin lives in San Diego. She bought a refrigerator for $1,624.99 and when the clerk calculated the sales tax it came out to exactly $142.186625. Round the sales tax to the nearest
ⓐ penny and
ⓑ dollar.
ⓐ $142.19; ⓑ $142
Sales Tax Jennifer bought a $1,038.99 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
ⓐ penny and
ⓑ dollar.
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.
ⓐ How much did she earn?
ⓑ If she had worked all 23 hours as a tutor instead of working both jobs, how much more would she have earned?
ⓐ $243.57 ⓑ $79.35
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.
ⓐ How much did he earn?
ⓑ If he had worked all 17 hours at the art gallery instead of working both jobs, how much more would he have earned?
How does knowing about US money help you learn about decimals?
Answers may vary
Explain how you write “three and nine hundredths” as a decimal.
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.
Answers may vary
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.
ⓐ After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.
ⓑ What does this checklist tell you about your mastery of this section? What steps will you take to improve?
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