Percents, Fractions and Decimals
Welcome to Study Guides!



Percent comes from the Latin words "per cent" which means "out of a hundred," like there are 100 cents in a dollar. So "ten per cent" means ten out of every hundred. A dime is ten percent of a dollar, and a dollar is ten percent of ten dollars.

If we say that 50% (fifty percent) of people are women, that means that fifty out of a hundred people are women, or half of the people. If we say that 100% of people have hearts, that means that all of them do.

To calculate a percentage for yourself, you need to understand how to multiply fractions and simplify equations. Suppose you have sixty-five seeds, and ten of them have gone moldy, and you need to know what percentage of the seeds went bad. First write your problem as a fraction: 10/65: ten out of sixty-five seeds went bad.

Now you need to know how much that would be out of a hundred, so set it up as an equation:

10/65 = x/100

To solve this equation and find out what x is, you'll need to find a common denominator for your two fractions. Just use 6500 (65x100). Remember to multiply the numerators by the same amount as the denominators! So you get:

solving above equation

Percentages can also be more than 100 percent. If you planted ten good seeds, and they grew into a hundred peas, you'd have 1000% of your original seeds back, or ten times as much. If you weigh 100 pounds, and your little brother weighs 50 pounds, you weigh 200% as much as he does, or twice as much.

More about Decimals
More about Fractions

Bibliography and further reading about numbers:

More about Percents
More about Fractions home

For Presidents' Day, check out our articles about Washington in the Revolutionary War and Lincoln in the Civil War. Find out about the Constitution, the Bill of Rights and the other Amendments, and how Washington promised to include freedom of religion.
Please help other teachers and students find us: link to this page from your class page.
Karen Carr is Associate Professor Emerita, Department of History, Portland State University. She holds a doctorate in Classical Art and Archaeology from the University of Michigan. Follow her on Instagram or Twitter.
Looking for more?
Cite this page
  • Author: K.E. Carr
  • Title:
  • Site Name: Study Guides
  • Publisher:
  • Date Published:
Proud of your class page, homework page, or resource page? Send it in and win a "Great Page!" award!
Sign up for more free articles and special offers in' weekly newsletter:
We will never share your e-mail address unless you allow us to do so. View our privacy policy. Easy unsubscribe links are provided in every email.
Comment on This Article

Cool stuff we've been enjoying: Looking for Valentine's gifts? Check out these new Chromebooks - all the computer you need for only $229.00!. Then study in peace with these Beats wireless headphones - for the exact same price! When you're done, show off your presentation or watch a movie with this excellent smartphone projector for only $39.99!

Does your class page honor diversity, celebrate feminism, and support people of color, LBGTQ people, and people with disabilities? Let us know, and we'll send you a Diversity Banner you can proudly display!
ADVERTISEMENT is loading comments...
(Comments will appear after moderation, if they are kind and helpful. Feel free to ask questions, and we'll try to answer them.)
Cite this page
  • Carr, K.E. . Study Guides, . Web. 21 February, 2017