Which is a common way for a scientific calculator to show the number below? 8.1 102

8.1e+2 or 8.1E+2 (in the scientific notation mode), based on that the number given is 8.1 × 10².

Explanation

Scientific calculators use the letter e or E to show the numbers in scientific notation mode.

These are some examples of numbers that require scientific notation and how they are shown.

Number                 Scientific calculator display

6.022 × 10²³           6.022 e+23
5 × 10 -12              5 E -12

So, understanding that your question is about number 8.1 × 10², the scientific calculator could show  8e+2.

Nevertheless, since 8 .1 × 10² is 810, not a long number, if the display is not in scientific notation mode, it could just display just 810,

Gas is a type of carbon, i think lol