# How do I use my scientific calculator?

It’s important to point out that each scientific calculator is a little different with regards to placement of certain keys as well as order of entry of keystrokes.

First, let’s start off with some basic operations, then move onto examples you can try with your scientific calculator.

Most calculators today have the following operations, which you need to know how to use:

 Operation What it means + plus, or addition - minus or subtraction Note: there is a DIFFERENT key to make a positive number into a negative number, perhaps marked (-) or NEG (for "negation") x times, or multiplied by ÷ over, or divided by yx or ^ raised to the power (for exponents) Sqrt or √ square root ex "exponentiate this," or raised to the power LN or ln natural logarithm, or "take the log of" sin sine function cos cosine function tan tangent function sin-1 inverse sine function, arcsine, or "the angle whose sine is" cos-1 inverse cosine function, arccosine, or "the angle whose cosine is" tan-1 inverse tangent function, arctangent, or "the angle whose tangent is" ( ) parentheses, or "do this first"

Enter the following expression into your calculator exactly as written and hit the “ENTER” or “=” key; you should obtain 41.

5 + 4 * 9
If you do not get 41, you do not have a scientific calculator that correctly evaluates mathematical expressions, and you will find it of little use in your science, mathematics, or engineering classes.

Working with Powers (Exponents)

When working with exponents, be sure to use the “yx ” or “^ ” key. "e" is that very special number (approximately 2.71828) which arises so often that it has been pre-programmed in your scientific calculator. Let’s try some examples:

To do 26, for most calculators, we punch the three keys “2 yx 6” or “2 ^ 6” (if your calculator has the yx, it might use the opposite order; i.e., “6 yx 2”). You may have to use the “SHIFT” or “2nd” function key in order to use the “yx ” or “ ^ ” key. We always punch the “ENTER” or “=” key to obtain our answer. Be sure to get the answer 64. If you’re in a test and you don’t remember the order in which to enter the numbers, don’t panic: just try the operation on something simple such as 23. You should obtain 8.

To do e6, for most calculators, we punch the two keys “ex 6” (some calculators use the opposite order; i.e., “6 ex”). You may have to use the “SHIFT” or “2nd” function key in order to use the “ex” key. Be sure to get the approximate answer 403.42879. 