<< Chapter < Page Chapter >> Page >
This module is from Fundamentals of Mathematics by Denny Burzynski and Wade Ellis, Jr. This module discusses how to round decimals. By the end of the module students should be able to round a decimal number to a specified position.

Section overview

  • Rounding Decimal Numbers

Rounding decimal numbers

We first considered the concept of rounding numbers in [link] where our concern with rounding was related to whole numbers only. With a few minor changes, we can apply the same rules of rounding to decimals.

To round a decimal to a particular position:

  1. Mark the position of the round-off digit (with an arrow or check).
  2. Note whether the digit to the immediate right of the marked digit is
    1. less than 5 . If so, leave the round-off digit unchanged.
    2. 5 or greater . If so, add 1 to the round-off digit.
  3. If the round-off digit is
    1. to the right of the decimal point, eliminate all the digits to its right.
    2. to the left of the decimal point, replace all the digits between it and the decimal point with zeros and eliminate the decimal point and all the decimal digits.

Sample set a

Round each decimal to the specified position. (The numbers in parentheses indicate which step is being used.)

Round 32.116 to the nearest hundredth.

  • 1 is in the hundredths position of 32.116

  • The digit immediately to the right is 6, and 6 > 5 size 12{"6 ">" 5"} {} , so we add 1 to the round-off digit:

    1 + 1 = 2 size 12{"1 "+" 1 "=" 2"} {}

  • The round-off digit is to the right of the decimal point, so we eliminate all digits to its right.

    32.12

The number 32.116 rounded to the nearest hundredth is 32.12.

Got questions? Get instant answers now!

Round 633.14216 to the nearest hundred.

  • 6 is in the hundreds position of 633.14216

  • The digit immediately to the right is 3, and 3 < 5 size 12{"3 "<" 5"} {} so we leave the round-off digit unchanged.
  • The round-off digit is to the left of 0, so we replace all the digits between it and the decimal point with zeros and eliminate the decimal point and all the decimal digits.

    600

The number 633.14216 rounded to the nearest hundred is 600.

Got questions? Get instant answers now!

1,729.63 rounded to the nearest ten is 1,730.

Got questions? Get instant answers now!

1.0144 rounded to the nearest tenth is 1.0.

Got questions? Get instant answers now!

60.98 rounded to the nearest one is 61.

Got questions? Get instant answers now!

Sometimes we hear a phrase such as "round to three decimal places." This phrase means that the round-off digit is the third decimal digit (the digit in the thousandths position).

67.129 rounded to the second decimal place is 67.13.

Got questions? Get instant answers now!

67.129558 rounded to 3 decimal places is 67.130.

Got questions? Get instant answers now!

Practice set a

Round each decimal to the specified position.

4.816 to the nearest hundredth.

4.82

Got questions? Get instant answers now!

0.35928 to the nearest ten thousandths.

0.3593

Got questions? Get instant answers now!

82.1 to the nearest one.

82

Got questions? Get instant answers now!

753.98 to the nearest hundred.

800

Got questions? Get instant answers now!

Round 43.99446 to three decimal places.

43.994

Got questions? Get instant answers now!

Round 105.019997 to four decimal places.

105.0200

Got questions? Get instant answers now!

Round 99.9999 to two decimal places.

100.00

Got questions? Get instant answers now!

Exercises

For the first 10 problems, complete the chart by rounding each decimal to the indicated positions.

20.01071

Tenth Hundredth Thousandth Ten Thousandth
Tenth Hundredth Thousandth Ten Thousandth
20.0 20.01 20.011 20.0107
Got questions? Get instant answers now!

3.52612

Tenth Hundredth Thousandth Ten Thousandth
3.53
Got questions? Get instant answers now!

531.21878

Tenth Hundredth Thousandth Ten Thousandth
Tenth Hundredth Thousandth Ten Thousandth
531.2 531.22 531.219 531.2188
Got questions? Get instant answers now!

36.109053

Tenth Hundredth Thousandth Ten Thousandth
36.1
Got questions? Get instant answers now!

1.999994

Tenth Hundredth Thousandth Ten Thousandth
Tenth Hundredth Thousandth Ten Thousandth
2.0 2.00 2.000 2.0000
Got questions? Get instant answers now!

7.4141998

Tenth Hundredth Thousandth Ten Thousandth
7.414
Got questions? Get instant answers now!

0.000007

Tenth Hundredth Thousandth Ten Thousandth

Tenth Hundredth Thousandth Ten Thousandth
0.0 0.00 0.000 0.0000

Got questions? Get instant answers now!

0.00008

Tenth Hundredth Thousandth Ten Thousandth
0.0001
Got questions? Get instant answers now!

9.19191919

Tenth Hundredth Thousandth Ten Thousandth

Tenth Hundredth Thousandth Ten Thousandth
9.2 9.19 9.192 9.1919

Got questions? Get instant answers now!

0.0876543

Tenth Hundredth Thousandth Ten Thousandth
Got questions? Get instant answers now!

Calculator problems

For the following 5 problems, round 18.4168095 to the indi­cated place.

3 decimal places.

18.417

Got questions? Get instant answers now!

5 decimal places.

18.41681

Got questions? Get instant answers now!

Calculator problems

For the following problems, perform each division using a calculator.

4 ÷ 3 size 12{"4 " div " 3"} {} and round to 2 decimal places.

Got questions? Get instant answers now!

1 ÷ 8 size 12{"1 " div " 8"} {} and round to 1 decimal place.

0.1

Got questions? Get instant answers now!

1 ÷ 27 size 12{"1 " div " 27"} {} and round to 6 decimal places.

Got questions? Get instant answers now!

51 ÷ 61 size 12{"51" div " 61"} {} and round to 5 decimal places.

0.83607

Got questions? Get instant answers now!

3 ÷ 16 size 12{"3 " div " 16"} {} and round to 3 decimal places.

Got questions? Get instant answers now!

16 ÷ 3 size 12{"16 " div " 3"} {} and round to 3 decimal places.

5.333

Got questions? Get instant answers now!

26 ÷ 7 size 12{"26 " div " 7"} {} and round to 5 decimal places.

Got questions? Get instant answers now!

Exercises for review

( [link] ) What is the value of 2 in the number 421,916,017?

Ten million

Got questions? Get instant answers now!

( [link] ) Perform the division: 378 ÷ 29 size 12{"378 " div " 29"} {} .

Got questions? Get instant answers now!

( [link] ) Find the value of 4 4 size 12{4 rSup { size 8{4} } } {} .

256

Got questions? Get instant answers now!

( [link] ) Convert 11 3 size 12{ { {"11"} over {3} } } {} to a mixed number.

Got questions? Get instant answers now!

( [link] ) Convert 3.16 to a mixed number fraction.

3 4 25 size 12{3 { {4} over {"25"} } } {}

Got questions? Get instant answers now!

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
How can I make nanorobot?
Lily
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
how can I make nanorobot?
Lily
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
7hours 36 min - 4hours 50 min
Tanis Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Fundamentals of mathematics. OpenStax CNX. Aug 18, 2010 Download for free at http://cnx.org/content/col10615/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Fundamentals of mathematics' conversation and receive update notifications?

Ask