How to subtract 20% on a calculator

Written by dirk huds Google
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to subtract 20% on a calculator
This equation on a calculator does not actually use the subtract button. (Thinkstock Images/Comstock/Getty Images)

Percentages can add another layer of complexity to mathematical equations. Combined with ordinal figures, subtraction of a percentage often requires patience and time to work out. While mental arithmetic is a useful skill to develop, sometimes speed is of the essence. Fortunately, subtracting a percentage from an ordinal number on a calculator is a straightforward operation.

Skill level:
Easy

Other People Are Reading

Things you need

  • Calculator

Show MoreHide

Instructions

  1. 1

    Turn on your calculator. Have the figure you wish to subtract 20 percent from at hand. You may need to add several figures together to get a total from which to take away the percentage. This would be the case if you wish to subtract 20 percent from a select number of figures on a numerical list.

  2. 2

    Enter the figure from which you want to subtract 20 percent. In this example, use 150.

  3. 3

    Press the multiplication button on the calculator. It is symbolised by an “X.”

  4. 4

    Enter “0.8. This figure represents 80 percent (it is 80 percent of “1”). If you multiply a number by 80 percent, you are automatically subtracting 20 percent from it. In the example used, the equation would read “150 x 0.8.”

  5. 5

    Press the equals button, symbolised with the sign “=.” This will give you the result. In the above example the result is 120. You have subtracted 20 percent of 150.

Tips and warnings

  • It is always a good idea to repeat the calculation to double-check your answer, particularly if the equation is for a test or to calculate a payment.

Don't Miss

Filter:
  • All types
  • Articles
  • Slideshows
  • Videos
Sort:
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the eHow.co.uk site, you consent to the use of cookies. For more information, please see our Cookie policy.