Scientific Notation and Your Calculator
Dr. MJ Patterson
Now that we have established what scientific notation is all about (Module 0), we can look at using scientific notation on your calculator.
Each brand and model of calculator will operate in a slightly different fashion, so make sure to consult your user's manual and/or experiment to see how yours works. It might be helpful for future reference to print this page and write in just what keystrokes you need with your particular calculator.
Entering a Number in Scientific Notation
Most calculators have an EE or EXP key that you can use to enter a number in scientific notation. This key replaces the x 10 in the number.
For instance, to enter 6.02 x 1023, I would hit 6 . 0 2 EE 23 , or if my calculator had an EXP
key, I would hit 6 . 0 2 EXP 23
(A common error is to also enter x 10. Please notice that EE or EXP
replaces x 10.)
The calculator would display the number as follows:
|
6.02 23 |
|
|
|
|||
|
EE |
x2 |
log |
/ |
|
|
|
|
7 |
8 |
9 |
x |
|
|
|
|
4 |
5 |
6 |
- |
|
|
|
|
1 |
2 |
3 |
+ |
|
|
|
|
0 |
. |
+/- |
= |
|
|
|
In the display, the exponent or power of 10 is usually written a little bit differently than the base of the number. It might be smaller in size, or it might even be raised slightly higher than the base. Note that the x 10 is not explicitly written in the display!
Entering a Number in Scientific Notation with a Negative Exponent
Experiment with your calculator to see what method works best with a negative exponent. I'll propose two routes to try.
1. If you have an older calculator (like mine!), you have to hit the change sign key (+/-) after entering the exponent.
To enter 1.6 x 10-19, I would enter 1 . 6 EE 1 9 +/-
2. If you have a calculator that lets you enter numbers in a manner much closer to how they are written on a page, you can hit the change sign key before entering the exponent.
To enter 1.6 x 10-19, you would enter 1 . 6 EE +/- 1 9
The number should appear on you calculator like the example below.
|
1.6 -19 |
|
|
|
|||
|
EE |
x2 |
log |
/ |
|
|
|
|
7 |
8 |
9 |
x |
|
|
|
|
4 |
5 |
6 |
- |
|
|
|
|
1 |
2 |
3 |
+ |
|
|
|
|
0 |
. |
+/- |
= |
|
|
|
Controlling the Display Mode
Most calculators normally display numbers in conventional notation. You can also force your calculator to display all numbers in scientific notation. If the following suggestions do not work on your calculator, consult your user manual.
Look for two options labelled FLO and SCI. These stand for floating decimal point (conventional) and scientific notation. These are frequently found above a number key. You will have to use the 2nd function key to access them. In other words, if SCI is above the 5 key, you would have to hit the 2nd function key and then immediately the 5 key to use it. The 2nd function key acts like a shift key on a keyboard. This key sequence should place the display into scientific notation.
To return to conventional notation, hit the 2nd function key followed immediately by the FLO (or 4, or whatever number is printed there) key.
(Many calculators have a third option - ENG - or engineering notation. This is similar to scientific notation, but it forces the exponent to be a multiple of three, corresponding to the metric units such as kg, mg,...)
Examples:
Work the following problems and check your answers to make sure you are
entering numbers in scientific notation correctly.
Solutions: