Title: Unit 3 Quiz
Course: Technical Math for Industry

Q: What is the place value of the 7 in 6.857?
- thousandths (Correct. The digit 7 is three decimal places to the right of the decimal point, which means that it is in the thousandths place.)
- hundreds (Incorrect. The digit 7 is to the right of the decimal point, which means that it is less than 1 and on the th side.)
- hundredths (Incorrect. The digit 7 is three decimal places to the right of the decimal point, not two.)
- thousands (Incorrect. The digit 7 is to the right of the decimal point, which means that it is less than 1 and on the th side.)
A: thousandths

Q: Write 0.085 as a simplified fraction.
A: (a choice with no text)
If wrong: Incorrect. You may have simplified . You need to simplify .
If wrong: Incorrect. You may have divided 85 by 10,000 instead of by 1,000.
If wrong: Incorrect. This is an equivalent fraction, but it is not simplified.
If right: Correct. The number 0.085 can be written as , which simplifies to .

Q: Convert to a decimal.
- 6.12 (Correct. ;)
- 6.03 (Incorrect. The decimal part of this answer is the result of dividing 3 by 100. You need to divide 3 by 25 to get a decimal, and then add the result to 6.)
- 6.012 (Incorrect. , not .012. When you use long division, make sure that your decimal points line up.)
A: 6.12
If wrong: Incorrect. You may have divided 25 by 3. You need to divide 3 by 25 to get the decimal, and then add the result to 6.

Q: Which of the following sentences is true? Use the number line to help you decide.
- 6.2 is less than 5.7. (Incorrect. Check to see if 6.2 is to the right or left of of 5.7 on the number line.)
- 6.1 is greater than 5.9. (Correct. 6.1 is to the right of 5.9 on the number line, so 6.1 is greater than 5.9.)
- 6.0 is less than 5.8. (Incorrect. Check to see if 6.0 is to the right or left of 5.8 on the number line.)
- 5.5 is greater than 5.7. (Incorrect. Check to see if 5.5 is to the right or left of 5.7 on the number line.)
A: 6.1 is greater than 5.9.

Q: Which of the following sentences is true?
- 5.324 is less than 5.314. (Incorrect. In the hundredths place, 2 is greater than 1, while the digits in the other places are the same. This makes the first number greater than the second number.)
- 82.349 is less than 82.347. (Incorrect. In the thousandths place, 9 is greater than 7, while the digits in the other places are the same. This makes the first number greater than the second number.)
- 20.544 is greater than 20.844. (Incorrect. In the tenths place, 5 is less than 8, while the digits in the other places are the same. This makes the first number less than the second number.)
- 19.532 is greater than 19.522. (Correct. In the hundredths place, 3 is greater than 2, while the digits in the other places are the same. This makes the first number greater than the second number.)
A: 19.532 is greater than 19.522.

Q: Which of the following sentences is true?
A: (a choice with no text)
If wrong: Incorrect. Remember that . Now compare the digits of and . The digits in the tens and ones place are the same. Comparing the tenths place, , so .
If right: Correct. , and because the digits are the same until the thousandths place, and in the thousandths place 0 is less than 6.
If wrong: Incorrect. The digits in the tens and ones place are the same. Comparing the digits in the tenths place, , so .
If wrong: Incorrect. The digits are the same until the hundredths place, where , so .

Q: Round 8,295.357 to the nearest tenth.
- 8,295.36 (Incorrect. You rounded to the nearest hundredth. You should have rounded to the nearest tenth.)
- 8,300 (Incorrect. You rounded to the nearest ten. You should have rounded to the nearest tenth.)
- 8,295.4 (Correct. You were right to round up, because there is a 5 in the hundredths place.)
- 8,295.3 (Incorrect. You rounded down when you should have rounded up.)
A: 8,295.4

Q: Add.
- 30.266 (Incorrect. This would have been correct for the problem . You can only add zeros at the end of a decimal.)
- 93.86 (Incorrect. This would have been correct for the problem . Pay attention to the placement of decimal points.)
- 30.86 (Incorrect. This would have been correct for the problem . You can only remove zeros from the end of a decimal.)
- 30.32 (Correct. Line up the decimal points and then add.)
A: 30.32

Q: Subtract.
- 19.044 (Incorrect. This would have been correct for the problem . You can only add zeros to the end of a decimal.)
- 19.44 (Incorrect. This would have been correct for the problem . You can only remove zeros from the end of a decimal.)
- 19.665 (Correct. Line up the two numbers so that the decimal points are aligned, and then subtract.)
- 19.584 (Incorrect. This would have been correct for the problem . You can only add zeros to the end of a decimal.)
A: 19.665

Q: Martin has a $200 gift card to a bookstore. He used the card to spend $56.74 on books. How much is left on the gift card?
- $144.74 (Incorrect. This would be the result of the subtraction .)
- $256.74 (Incorrect. Subtract the amount spent from the value of the card. Don't add the amount to it.)
- $143.26 (Correct.)
- $144.26 (Incorrect. Don't forget to take away a 1 in the ones place when regrouping.)
A: $143.26

Q: Multiply.
- 0.306228 (Incorrect. Pay attention to the placement of the decimal point. The factors have a total of four decimal places, so the product should also have four decimal places.)
- 30.6228 (Correct. To find the product, multiply . Count the total number of decimal places in the factors, four, and then place a decimal point in the product so that the product has four decimal places as well.)
- 3.06228 (Incorrect. Pay attention to the placement of the decimal point. The factors have a total of four decimal places, so the product should also have four decimal places.)
- 306.228 (Incorrect. Pay attention to the placement of the decimal point. The factors have a total of four decimal places, so the product should also have four decimal places.)
A: 30.6228

Q: Multiply.
- 0.451200 (Incorrect. When multiplying a decimal by 100, do not add two zeros to the right of the decimal. Instead, move the decimal point two places to the right.)
- 45.12 (Correct. To multiply a decimal number by a power of ten (such as , , , etc.), count the number of zeros in the power of ten. Then move the decimal point that number of places to the right.)
- 0.004512 (Incorrect. You moved the decimal point two places to the left, but it should be moved two places to the right.)
- 4.512 (Incorrect. You moved the decimal point one place to the right, but it should be moved two places to the right.)
A: 45.12

Q: Divide.
- 15.01 (Incorrect. You may have moved the decimal point in 0.15 and forgotten to move the decimal point in 225.15. Move the decimal point in both numbers two places to the right. (This will replace 0.15 with a whole number.) Then divide.)
- 150.1 (Incorrect. Multiply both the divisor and the dividend by 100. (This will replace 0.15 with a whole number). Then divide.)
- 1,501 (Correct. This problem can be set up as .)
- 225 (Incorrect. This is a division problem, not a subtraction problem.)
A: 1,501

Q: Divide.
- 3,542.3 (Incorrect. The decimal point has been moved two places to the right. This would be the answer if you multiplied by 100.)
- 0.35423 (Correct. 100 has two zeros, so the decimal point gets moved two places to the left.)
- 0.035423 (Incorrect. The decimal point has been moved three places to the left. You should count the number of zeros, not the number of digits, in 100. The decimal point should be moved two places to the left.)
- 0.0035423 (Incorrect. 100 has two zeros, so the decimal point gets moved two places to the left. This is not the same as having two zeros after the decimal point.)
A: 0.35423

Q: A motorcyclist rides 945.50 miles, using 30.5 gallons of gasoline. What is the mileage, in miles per gallon?
- 0.31 miles per gallon (Incorrect. If you were multiplying, you would add the number of decimal places, but you don't do this when dividing. Multiply the dividend and the divisor by 10, so that the problem becomes .)
- 28,837.75 miles per gallon (Incorrect. This is the product of the two numbers. You must divide the number of miles by number of gallons.)
- 310 miles per gallon (Incorrect. This would be the result of dividing . You need to move the decimal point the same number of places in the dividend and divisor.)
- 31 miles per gallon (Correct. Divide the number of miles by the number of gallons.)
A: 31 miles per gallon

Q: Marian went shopping and bought clothes for $66.17 and books for $44.98. She then had a meal at the mall for $20.15. Which is the best estimate of the total cost of her shopping trip?
- $130 (Correct. $66.17 rounds to 65, $44.98 to 45, and $20.15 to 20. Then .)
- $120 (Incorrect. You may have rounded $66.17 to $60 and $44.98 to $40. Using $65 and $45 will give you a better estimate.)
- $110 (Incorrect. You may have left out the meal for about $20.)
- $140 (Incorrect. You may have rounded $66.17 to $70 and $44.98 to $50. Using $65 and $45 will give you a better estimate.)
A: $130