ACCUPLACER Arithmetic Quiz: Rounding Decimals
20 questions · exam conditions
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Rounding DecimalsQuestion 1 of 20

A pharmacist measures 127.6384 mL of liquid medication. Prescription labels must show volumes rounded to the nearest 2.5 mL increment for safety reasons. What volume should appear on the label?

125.0 mL
130.0 mL
127.5 mL
128.0 mL
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ACCUPLACER Arithmetic Quiz

ACCUPLACER Arithmetic Quiz: Rounding Decimals

Practice Rounding Decimals in ACCUPLACER Arithmetic with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Rounding Decimals, giving you a quick way to practice the rules, question types, and explanations that matter most for ACCUPLACER Arithmetic.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A pharmacist measures 127.6384 mL of liquid medication. Prescription labels must show volumes rounded to the nearest 2.5 mL increment for safety reasons. What volume should appear on the label?

  1. 125.0 mL
  2. 130.0 mL
  3. 127.5 mL (correct answer)
  4. 128.0 mL
Explanation: This question tests your ability to round to non-standard increments, which appears frequently in real-world applications like pharmacy, manufacturing, and measurement scenarios. To round 127.6384 mL to the nearest 2.5 mL increment, you need to identify which multiples of 2.5 the given value falls between. The key multiples are: 125.0, 127.5, and 130.0 mL. Since 127.6384 falls between 127.5 and 130.0, you must determine which it's closer to. The distance from 127.6384 to 127.5 is 127.6384−127.5=0.1384127.6384 - 127.5 = 0.1384 mL. The distance from 127.6384 to 130.0 is 130.0−127.6384=2.3616130.0 - 127.6384 = 2.3616 mL. Since 0.1384 is much smaller than 2.3616, the measurement rounds to 127.5 mL. Answer A (125.0 mL) represents rounding down to the wrong increment—this would be correct if you mistakenly looked at 125.0 and 127.5 as your boundary values. Answer B (130.0 mL) incorrectly rounds up to the farther increment, possibly from confusing standard rounding rules. Answer D (128.0 mL) shows rounding to the nearest whole number instead of the required 2.5 mL increment, missing the specific constraint entirely. When rounding to non-standard increments, always identify the multiples above and below your target number first, then calculate which is closer. Don't default to familiar rounding rules—pay close attention to the specific increment required.

Question 2

A wooden board is 5 meters long. A piece measuring 2.185 meters is cut from it. What is the length of the remaining piece, rounded to the nearest tenth of a meter?

  1. 2.8 m (correct answer)
  2. 2.9 m
  3. 2.81 m
  4. 2.82 m
Explanation: First, find the length of the remaining piece by subtracting: 5−2.185=2.8155 - 2.185 = 2.815 meters. Next, round this result to the nearest tenth. The digit in the hundredths place is 1, which is less than 5, so we round down. The result is 2.8 meters.

Question 3

Two numbers, A = 1.049 and B = 1.051, are rounded to the nearest hundredth. How does the rounded value of A compare to the rounded value of B?

  1. The rounded value of A is less than the rounded value of B.
  2. The rounded value of A is equal to the rounded value of B. (correct answer)
  3. The rounded value of A is greater than the rounded value of B.
  4. The comparison depends on the next decimal place.
Explanation: First, round A (1.049) to the nearest hundredth. The thousandths digit is 9, so we round up to 1.05. Next, round B (1.051) to the nearest hundredth. The thousandths digit is 1, so we round down to 1.05. Both numbers round to 1.05, so their rounded values are equal.

Question 4

To estimate the product of 4.87 and 19.75, a student rounds each number to the nearest whole number before multiplying. What is the student's estimate?

  1. 80
  2. 95
  3. 96
  4. 100 (correct answer)
Explanation: The problem requires rounding before multiplying. First, round 4.87 to the nearest whole number, which is 5. Next, round 19.75 to the nearest whole number, which is 20. Finally, multiply the rounded numbers: 5×20=1005 \times 20 = 100.

Question 5

A deep-sea probe descends 13.578 meters from a platform that is 2.8 meters below sea level. What is the probe's final depth below sea level, rounded to the nearest hundredth of a meter?

  1. 16.37 m
  2. 16.3 m
  3. 16.38 m (correct answer)
  4. 16.4 m
Explanation: To find the final depth, add the platform's depth to the probe's descent: 2.8+13.578=16.3782.8 + 13.578 = 16.378 meters. To round this to the nearest hundredth, look at the thousandths digit, which is 8. Since 8 is 5 or greater, we round up the hundredths digit. The final depth is 16.38 meters.

Question 6

When rounded to the nearest tenth, a number is 10.4. Which of the following could be the original number?

  1. 10.349
  2. 10.448 (correct answer)
  3. 10.45
  4. 10.49
Explanation: For a number to round to 10.4 (nearest tenth), it must be greater than or equal to 10.35 and less than 10.45. The number 10.448 falls within this range [10.35, 10.45).

Question 7

A store sells apples for ($1.99) per pound. A customer buys a bag of apples weighing 3.5 pounds.

The total cost is calculated and then rounded to the nearest cent. What is the final cost?

  1. $6.96
  2. $6.97 (correct answer)
  3. $7.00
  4. $7.07
Explanation: First, calculate the total cost by multiplying the price per pound by the weight: ($1.99 \times 3.5 = 6.965). The nearest cent is the hundredths place. Since the digit in the thousandths place is 5, we round up the hundredths digit. Therefore, ($6.965) rounds to ($6.97).

Question 8

A construction project requires boards cut to 8.4375 feet in length. The saw can only make cuts accurate to the nearest sixteenth of a foot. If 8.4375 feet equals 87168\frac{7}{16} feet exactly, what length should be cut?

  1. 88168\frac{8}{16} feet
  2. 86168\frac{6}{16} feet
  3. 87168\frac{7}{16} feet (correct answer)
  4. 85168\frac{5}{16} feet
Explanation: This question tests your understanding of precision and accuracy in measurement. When a problem states that something "equals exactly" a certain value but the measuring tool has limited precision, you need to determine what the tool would actually read. The problem tells you that 8.4375 feet equals 87168\frac{7}{16} feet exactly, and the saw can only cut accurately to the nearest sixteenth of a foot. Since the desired length is already expressed as a fraction with sixteenths (87168\frac{7}{16}), and this falls exactly on a marking the saw can make, no rounding is needed. The saw should be set to cut 87168\frac{7}{16} feet, making C correct. Looking at the wrong answers: A) 88168\frac{8}{16} represents rounding up to the next sixteenth, which would give you 8128\frac{1}{2} feet—unnecessarily long and wasteful. B) 86168\frac{6}{16} represents rounding down to the previous sixteenth, giving you 8388\frac{3}{8} feet—this would make the board too short for the project requirements. D) 85168\frac{5}{16} is even further from the target length, also making the board too short. The key insight is recognizing when no rounding is actually necessary. When dealing with precision problems, always check if the target value already matches the precision level of your measuring tool. If the exact measurement falls on a marking your tool can make, use that exact value rather than rounding unnecessarily.

Question 9

A bank calculates interest as 4.7825% annually, but must report the rate rounded to three decimal places on official documents, while advertising materials use the rate rounded to one decimal place. What is the sum of these two rounded rates?

  1. 9.565%
  2. 9.583% (correct answer)
  3. 9.575%
  4. 9.600%
Explanation: Round 4.7825% to three decimal places: look at the fourth decimal (5), so round up to 4.783%. Round 4.7825% to one decimal place: look at the second decimal (8), so round up to 4.8%. The sum is 4.783% + 4.8% = 9.583%. Choice A uses 4.782% + 4.8%, choice C uses 4.775% + 4.8%, and choice D uses 4.8% + 4.8%.

Question 10

A GPS device shows the distance to a destination as 47.8362 miles. The device's manual states that for battery conservation, distances over 25 miles should be displayed rounded to the nearest half-mile. What distance should be displayed?

  1. 47.5 miles
  2. 48.5 miles
  3. 47.8 miles
  4. 48.0 miles (correct answer)
Explanation: When you encounter rounding problems, you need to identify both the original value and the specific rounding rule being applied. Here, the GPS shows 47.8362 miles, and you must round to the nearest half-mile for distances over 25 miles. To round to the nearest half-mile, think of the number line marked in half-mile increments: 47.0, 47.5, 48.0, 48.5, etc. The value 47.8362 falls between 47.5 and 48.0. Since 47.8362 is closer to 48.0 (a difference of about 0.16) than to 47.5 (a difference of about 0.34), it rounds to 48.0 miles. This makes D correct. Let's examine why the other choices miss the mark. Choice A (47.5 miles) incorrectly rounds down when the original value is much closer to 48.0. Choice B (48.5 miles) rounds too far up—47.8362 is nowhere near the midpoint between 48.0 and 48.5. Choice C (47.8 miles) ignores the rounding instruction entirely and just truncates to one decimal place instead of following the half-mile rule. The key strategy for rounding problems is to first identify what increments you're rounding to (here, half-miles), then locate your number between two consecutive increments, and finally determine which increment is closer. Don't get confused by partial rounding—when the problem specifies "nearest half-mile," stick to that exact requirement rather than rounding to whole numbers or other decimal places.

Question 11

The lengths of two pipes, rounded to the nearest inch, are 8 inches and 12 inches. Which of the following is a possible actual total length of the two pipes?

  1. 18.9 inches
  2. 20.8 inches (correct answer)
  3. 21.0 inches
  4. 21.2 inches
Explanation: If a length rounds to 8 inches, its actual length is in the range [7.5, 8.5). If a length rounds to 12 inches, its actual length is in the range [11.5, 12.5). The minimum possible total length is 7.5+11.5=19.07.5 + 11.5 = 19.0 inches. The maximum possible total length is less than 8.5+12.5=21.08.5 + 12.5 = 21.0 inches. Therefore, the actual total length must be in the range [19.0, 21.0). Of the choices, only 20.8 inches is in this range.

Question 12

A student's scores on four assignments are 8.75, 9.2, 7.88, and 8.5. What is the sum of these scores, rounded to the nearest whole number?

  1. 33
  2. 34 (correct answer)
  3. 35
  4. 36
Explanation: First, find the sum of the scores: 8.75+9.2+7.88+8.5=34.338.75 + 9.2 + 7.88 + 8.5 = 34.33. Then, round the sum to the nearest whole number. The digit in the tenths place is 3, which is less than 5, so we round down to 34.

Question 13

What is the value of (3.5×2.1)+1.88(3.5 \times 2.1) + 1.88, rounded to the nearest whole number?

  1. 8
  2. 9 (correct answer)
  3. 10
  4. 11
Explanation: First, perform the multiplication: 3.5×2.1=7.353.5 \times 2.1 = 7.35. Next, perform the addition: 7.35+1.88=9.237.35 + 1.88 = 9.23. Finally, round the result to the nearest whole number. Since the tenths digit is 2 (which is less than 5), we round down to 9.

Question 14

A scientist records a temperature as 25.7°C after rounding it to the nearest tenth of a degree. Which of the following could NOT have been the original temperature measurement?

  1. 25.65°C
  2. 25.68°C
  3. 25.74°C
  4. 25.75°C (correct answer)
Explanation: Numbers that round to 25.7 must be in the range [25.65, 25.75). The number 25.75 is not in this range because, by convention, a number ending in 5 is rounded up. Therefore, 25.75 would be rounded to 25.8, not 25.7.

Question 15

A prize of ($500) is shared equally among 6 people. How much money does each person receive, rounded to the nearest cent?

  1. $83.00
  2. $83.30
  3. $83.33 (correct answer)
  4. $83.34
Explanation: To find each person's share, divide the total prize by the number of people: ($500 \div 6 = 83.333...). To round to the nearest cent (the hundredths place), look at the thousandths digit, which is 3. Since 3 is less than 5, we round down. Each person receives ($83.33).

Question 16

A runner completed three laps in 55.4 seconds, 56.9 seconds, and 58.1 seconds. What was the runner's average lap time, rounded to the nearest tenth of a second?

  1. 56.7 s
  2. 56.8 s (correct answer)
  3. 57.0 s
  4. 170.4 s
Explanation: First, find the total time: 55.4+56.9+58.1=170.455.4 + 56.9 + 58.1 = 170.4 seconds. Next, find the average by dividing the total time by the number of laps: 170.4÷3=56.8170.4 \div 3 = 56.8. Since the result is exactly 56.8, no rounding is needed.

Question 17

The number 3.846 is rounded to the nearest tenth. What is the absolute difference between the original number and the rounded number?

  1. 0.046 (correct answer)
  2. 0.054
  3. 0.146
  4. 0.154
Explanation: First, round 3.846 to the nearest tenth. The digit in the hundredths place is 4, so we round down, which gives 3.8. Then, find the absolute difference between the original number and the rounded number: ∣3.846−3.8∣=0.046|3.846 - 3.8| = 0.046.

Question 18

A pharmacist has 12.5 grams of a substance. She uses 4.875 grams for a prescription. Of the remaining substance, how much does she have, rounded to the nearest tenth of a gram?

  1. 7.6 g (correct answer)
  2. 7.7 g
  3. 7.62 g
  4. 7.63 g
Explanation: First, calculate the remaining amount: 12.5−4.875=7.62512.5 - 4.875 = 7.625 grams. Then, round this result to the nearest tenth. The digit in the hundredths place is 2, which is less than 5, so we round down. The result is 7.6 grams.

Question 19

A rope measuring 15.8 meters is cut into 3 equal pieces. What is the length of each piece, rounded to the nearest hundredth of a meter?

  1. 5.26 m
  2. 5.27 m (correct answer)
  3. 5.3 m
  4. 5.30 m
Explanation: First, divide the total length of the rope by the number of pieces: 15.8÷3=5.2666...15.8 \div 3 = 5.2666.... Next, round this result to the nearest hundredth. The digit in the thousandths place is 6, which is 5 or greater, so we round up the hundredths digit. 5.26 becomes 5.27.

Question 20

A floor tile is a square with a side length of 0.35 meters. What is the area of the tile, in square meters, rounded to the nearest tenth?

  1. 0.1 (correct answer)
  2. 0.2
  3. 0.3
  4. 0.4
Explanation: The area of a square is the side length multiplied by itself. Area = 0.35×0.35=0.12250.35 \times 0.35 = 0.1225 square meters. To round this to the nearest tenth, we look at the hundredths digit, which is 2. Since 2 is less than 5, we round down, and the area is 0.1 square meters.