How to Use Exponents on a Scientific Calculator

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Scientific calculators have more functionality that business calculators, and one thing they can do that is especially useful for scientists is to calculate exponents. On most calculators, you access this function by typing the base, the exponent key and finally the exponent. Although this is the convention, it's always good to do a test, because some calculators may require you to enter the numbers in reverse order.

Scientific Vs. Business Calculators

Scientific calculators are easy to distinguish from business calculators because of their many extra function keys. If you aren't sure if you have a scientific calculator, try this calculation:

Enter (3+2*5 =) in that order. A scientific calculator will automatically do the multiplication first and give 13 as the answer. A business calculator will do the operations in the order you enter them and give 25.

Here are just a few of the functions on a scientific calculator that you won't find on a business calculator:

  • Negation: This key, denoted by NEG or (-) turns a positive number into a negative one. It is different from the subtraction key.
  • Square Root: Denoted by the square root sign, it automatically displays the square root of the number you enter.
  • Natural Logarithm: Denoted by LN, this key displays loge of the number you enter. 
  • Angle Functions: Scientific calculators have six keys the display the sine, cosine, tangent and the inverse of each for the number you enter.

In addition to these keys, scientific calculators usually have two keys for exponential functions:

  • Exponent: The key denoted by ^ or by capital E raises ay number to any exponent. 
  • Natural Exponent: The key, denoted by ex, raises e to the power you enter. 

Using the Exponent Key

Suppose you want the value yx. On most calculators, you enter the base, press the exponent key and enter the exponent. Here's an example:

Enter 10, press the exponent key, then press 5 and enter. (10^5=) The calculator should display the number 100,000, because that's equal to 105. Before you start making a list of calculations, however, you should do a simple test to make sure your calculator isn't one of those that requires you to input the exponent first.

Enter the number 2, press the exponent key, then enter 3. The display should read 8. If it reads 9, that's because the calculator interpreted the input as 32 instead of 23. That means you need to enter the exponent before the base.

Some calculators have a key marked yx. This is the same as the ^ key. To find 105, enter 10, then the yx key, then 5 and hit the Enter or = key.

Reading Exponents

Some numbers, such as 265 billion, have too many digits to display on a calculator. When this happens, the calculator displays the number in scientific notation, using the letter E to denote 10 to the power of whatever number comes after it. For example, 265 billion appears on a scientific calculator as 2.65 E 11.

You can add, subtract, multiply and divide large numbers just as you would small ones, and the results will continue to appear in scientific notation a long as they continue to have too many digits to display.

Examples:

2.65 E 8 + 5.78 E 7 = 3.23 E 8.

2.65 E 8 / 5.78 E 7 = 4.58

References

About the Author

Chris Deziel holds a Bachelor's degree in physics and a Master's degree in Humanities, He has taught science, math and English at the university level, both in his native Canada and in Japan. He began writing online in 2010, offering information in scientific, cultural and practical topics. His writing covers science, math and home improvement and design, as well as religion and the oriental healing arts.

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