How to Use a Basic Calculator

Even if you know how to do basic arithmetic, a calculator saves you time and effort when you need a quick answer.

Simple Equations

A calculator is a handy tool.A calculator is a handy tool.
It is a handy tool for performing simple, everyday math--like you may need for budgeting or grocery shopping--without pencil and paper.

Press the "On" button to begin.

Type the first number of the equation you want to solve.

Press the key for the operation you want to perform: division (÷), multiplication (X), subtraction (-), or addition (+).

Type the number you are adding, subtracting, multiplying or dividing.

Press the equals (=) sign key.


Type in the number you need to know a percentage of.

Press the multiplication (X) key.

Type in the percentage amount you want to know.

Press the percentage (%) key.

Square Root

Type the number whose square root you wish to find.

Press the square root ('√') key.

Press the "C" key to clear the display, if you wish to solve another equation.

Things You Will Need

  • Calculator


  • A calculator has memory that is able to temporarily store values. To store a number in memory, press the "MS" key. To bring up the value kept in the memory, use the "MR" key. To add to the value in the memory, press the "M+" key. Once you bring up a stored number using the "MR" key you can use the regular function keys to perform whatever operation you need. To clear the memory, press the "MC" key.
  • You can perform longer computations as long as you do not press the "C" key. The "C" key clears all input to the calculator while the "CE" key clears just the most recent entry. Use the "CE" key if you make a mistake in a long computation--this way you won't need to begin over again.

About the Author

Wanda Brito was born to write. She has written professionally since 1998 - developing surveys, presentations and marketing research reports — and has been writing and proofreading freelance since 2007. Her work has been featured on She holds a Bachelor of Arts in Spanish literature from Colgate University and a Master of Science in administration from Metropolitan College of New York.