<< Chapter < Page Chapter >> Page >
By the end of this section, you will be able to:
  • Name and write decimals
  • Round decimals
  • Add and subtract decimals
  • Multiply and divide decimals
  • Convert decimals, fractions, and percents

A more thorough introduction to the topics covered in this section can be found in the Prealgebra chapter, Decimals .

Name and write decimals

Decimals are another way of writing fraction    s whose denominators are powers of 10.

0.1 = 1 10 0.1 is “one tenth” 0.01 = 1 100 0.01 is “one hundredth” 0.001 = 1 1,000 0.001 is “one thousandth” 0.0001 = 1 10,000 0.0001 is “one ten-thousandth”

Notice that “ten thousand” is a number larger than one, but “one ten-thousand th ” is a number smaller than one. The “th” at the end of the name tells you that the number is smaller than one.

When we name a whole number, the name corresponds to the place value based on the powers of ten. We read 10,000 as “ten thousand” and 10,000,000 as “ten million.” Likewise, the names of the decimal    places correspond to their fraction values. [link] shows the names of the place values to the left and right of the decimal point.

A table is shown with the title Place Value. From left to right the row reads “Hundred thousands,” “Ten thousands,” “Thousands,” “Hundreds,” “Tens,” and “Ones.” Then there is a blank cell and below it is a decimal point. To the right of this, the cells read “Tenths,” “Hundredths,” “Thousandths,” “Ten-thousandths,” and “Hundred-thousandths.”
Place value of decimal numbers are shown to the left and right of the decimal point.

How to name decimals

Name the decimal 4.3.

Solution

A table is given with four steps. Additionally, the number 4.3 is given. The first step reads “Step 1. Name the number to the left of the decimal point.” To the right of this, it is noted that “4 is to the left of the decimal point.” To the right of this, it reads “four” followed by a large blank space. The second step reads “Step 2. Write ‘and’ for the decimal point.” To the right of this it reads “four and” followed by a blank space. The third step reads “Step 3. Name the ‘number’ part to the right of the decimal point as if it were a whole number.” To the right of this, it reads “3 is to the right of the decimal point.” To the right of this, it reads “four and three” followed by a blank. Finally, the last step reads “Step 4. Name the decimal place.” To the right of this, it reads “four and three tenths.”
Got questions? Get instant answers now!
Got questions? Get instant answers now!

Name the decimal: 6.7 .

six and seven tenths

Got questions? Get instant answers now!

Name the decimal: 5.8 .

five and eight tenths

Got questions? Get instant answers now!

We summarize the steps needed to name a decimal    below.

Name a decimal.

  1. Name the number to the left of the decimal point.
  2. Write “and” for the decimal point.
  3. Name the “number” part to the right of the decimal point as if it were a whole number.
  4. Name the decimal place of the last digit.

Name the decimal: −15.571 .

Solution

−15.571 Name the number to the left of the decimal point. negative fifteen __________________________________ Write “and” for the decimal point. negative fifteen and ______________________________ Name the number to the right of the decimal point. negative fifteen and five hundred seventy-one __________ The 1 is in the thousandths place. negative fifteen and five hundred seventy-one thousandths

Got questions? Get instant answers now!
Got questions? Get instant answers now!

Name the decimal: −13.461 .

negative thirteen and four hundred sixty-one thousandths

Got questions? Get instant answers now!

Name the decimal: −2.053 .

negative two and fifty-three thousandths

Got questions? Get instant answers now!

When we write a check we write both the numerals and the name of the number. Let’s see how to write the decimal from the name.

How to write decimals

Write “fourteen and twenty-four thousandths” as a decimal.

Solution

A table is given with four steps. The first step reads “Step 1. Look for the work ‘and’ – it locates the decimal point. Place a decimal point under the word ‘and’. Translate the words before ‘and’ into the whole number and place it to the left of the decimal point.” To the right of this, we have the words “fourteen and twenty-four thousandths.” Below this word, we have “fourteen and twenty-four thousandths” with the word “and” underlined. Below this word, we have a small blank space separated from a larger blank space by a decimal point. Under this, we have 14 in the small blank space followed by the decimal point and the larger blank space. The second step reads “Step 2. Mark the number of decimal places needed to the right of the decimal point by noting the place value indicated by the last word.” To the right of this it reads “The last word is thousandths.” To the right of this there is the number 14 followed by a decimal point and three small blank spaces. Under the blank spaces, the words “tenths,” “hundredths,” and “thousandths” are written. The third step reads “Step 3. Translate the words after ‘and’ into the number to the right of the decimal point. Write the number in the spaces – putting the final digit in the last place.” To the right of this, we have 14 followed by a decimal followed by a blank space followed by 2 and 4 on the other two previously blank spaces. Finally, the last step reads “Step 4. Fill in zeros for empty place holders as needed.” To the right of this, it reads “Zeros are needed in the tenths place.” To the right of this, we have 14 followed by a decimal point followed by 0, 2, and 4, respectively, on the blank spaces. Below this, we have “fourteen and twenty-four thousandths is written 14.024.”
Got questions? Get instant answers now!
Got questions? Get instant answers now!

Write as a decimal: thirteen and sixty-eight thousandths.

13.68

Got questions? Get instant answers now!

Write as a decimal: five and ninety-four thousandths.

5.94

Got questions? Get instant answers now!

We summarize the steps to writing a decimal    .

Write a decimal.

  1. Look for the word “and”—it locates the decimal point.
    • Place a decimal point under the word “and.” Translate the words before “and” into the whole number and place it to the left of the decimal point.
    • If there is no “and,” write a “0” with a decimal point to its right.
  2. Mark the number of decimal places needed to the right of the decimal point by noting the place value indicated by the last word.
  3. Translate the words after “and” into the number to the right of the decimal point. Write the number in the spaces—putting the final digit in the last place.
  4. Fill in zeros for place holders as needed.

Questions & Answers

if three forces F1.f2 .f3 act at a point on a Cartesian plane in the daigram .....so if the question says write down the x and y components ..... I really don't understand
Syamthanda Reply
hey , can you please explain oxidation reaction & redox ?
Boitumelo Reply
hey , can you please explain oxidation reaction and redox ?
Boitumelo
for grade 12 or grade 11?
Sibulele
the value of V1 and V2
Tumelo Reply
advantages of electrons in a circuit
Rethabile Reply
we're do you find electromagnetism past papers
Ntombifuthi
what a normal force
Tholulwazi Reply
it is the force or component of the force that the surface exert on an object incontact with it and which acts perpendicular to the surface
Sihle
what is physics?
Petrus Reply
what is the half reaction of Potassium and chlorine
Anna Reply
how to calculate coefficient of static friction
Lisa Reply
how to calculate static friction
Lisa
How to calculate a current
Tumelo
how to calculate the magnitude of horizontal component of the applied force
Mogano
How to calculate force
Monambi
a structure of a thermocouple used to measure inner temperature
Anna Reply
a fixed gas of a mass is held at standard pressure temperature of 15 degrees Celsius .Calculate the temperature of the gas in Celsius if the pressure is changed to 2×10 to the power 4
Amahle Reply
How is energy being used in bonding?
Raymond Reply
what is acceleration
Syamthanda Reply
a rate of change in velocity of an object whith respect to time
Khuthadzo
how can we find the moment of torque of a circular object
Kidist
Acceleration is a rate of change in velocity.
Justice
t =r×f
Khuthadzo
how to calculate tension by substitution
Precious Reply
hi
Shongi
hi
Leago
use fnet method. how many obects are being calculated ?
Khuthadzo
khuthadzo hii
Hulisani
how to calculate acceleration and tension force
Lungile Reply
you use Fnet equals ma , newtoms second law formula
Masego
please help me with vectors in two dimensions
Mulaudzi Reply
how to calculate normal force
Mulaudzi
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply
Practice Key Terms 3

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Elementary algebra. OpenStax CNX. Jan 18, 2017 Download for free at http://cnx.org/content/col12116/1.2
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Elementary algebra' conversation and receive update notifications?

Ask