# What are the uses of scientific notation

## Handheld calculator use

### Scientific notation with a handheld calculator

To enter numbers in scientific notation into a handheld calculator, there is usually a button labeled "E" or "EE" that is used to enter the correct power of ten. For example, to get the mass of a proton in grams (1.67 x 10 -24 Grams) into a handheld calculator, I enter the following keystrokes:

(1) (.) (6) (7) (EE) (2) (4) (+/-)

Pressing the (+/-) key changes the sign of the power (24) to -24. Some calculators allow the subtraction (-) key to be used to do this, but I prefer the change sign (+/-) key because it is more consistent with using that key in other contexts.

If I were to enter a negative number in scientific notation into a handheld calculator, I would have to be careful how I used the (+/-) key so that I was changing the sign of the power rather than the significant place value. Follow this example:

Number to be recorded: -3.221 x 10 -15 :

(3) (.) (2) (2) (1) (+/-) (EE) (1) (5) (+/-)

The first (+/-) keystroke changes the entry from 3.221 to -3.221; The second (+/-) push of the button changes the power from 15 to -15.

### Display modes for metric and scientific notations

Representing metric and scientific notation on a calculator is a different matter. To do this, the display option must be changed from the normal "fixed" decimal point mode to the "scientific" or "technical" mode. Refer to your calculator manual to learn how to set each display mode.

These display modes tell the calculator how to display a number on the numeric display. The actual value of the number is in no way affected by the choice of display modes - just how the number is displayed to the user of the calculator. Likewise, the method of entering numbers into the calculator does not change with different display modes. Powers of ten are usually represented by a pair of digits in the upper right corner of the display and are only visible in the "Scientific" and "Engineering" modes.

The difference between "scientific" and "technical" display modes is the difference between scientific and metric notation. In the "Scientific" mode, the display of the power of ten is set so that the main number on the display always has a value between 1 and 10 (or -1 and -10 for negative numbers). In "Engineering" mode, the powers of ten are set so that they are displayed in multiples of 3 to represent the most important metric prefixes. All the user has to do is memorize a few Prefix / Power combinations and his calculator will "speak" metric!

POWER METRIC PREFIX ----- ------------- 12 ……… Tera (T) 9 ………. Giga (G) 6 ………. Mega (M) 3 ………. Kilo (k) 0 ………. UNITS (simple) -3… …… Milli (m) -6 ……… Micro (u) -9 ……… Nano (n) -12 …… .. Pico (p)
• REVIEW:
• Use the (EE) key to enter powers of ten.
• Use Scientific or Engineering to display powers of ten in scientific or metric notation.