SI Prefixes

The table below shows some of the most common SI prefixes, abbreviations, and the meanings of those prefixes. You should familiarize yourself with the table.

## Matching Definitions With SI Prefixes

Scroll to the top of the page and read the material if you have not already. When you are ready to complete the exercise, match the items on the right to the items on the left.

## SI Prefixes Example 1:

Question: How many seconds are in 1 Ts?

Answer: T is the abbreviation for tera, and s is the abbreviation for second. So, 1 Ts is the same thing as 1 terasecond. We need to figure out what tera means. To do that, we just look at the table above. According to the table, tera means 10^12 (10 raised to the 12th power). So, 1 terasecond is the same thing as 1 x 10^12 seconds. 10^12 is the same thing as 1 trillion.

If you do not know how to convert from 10^12 to 1 trillion, click HERE.

Thus, 1 terasecond is 1 x 10^12 seconds = 1 trillion seconds = 1,000,000,000,000 seconds. Note: Any of the above methods for writing 1 trillion seconds is acceptable.

Answer: T is the abbreviation for tera, and s is the abbreviation for second. So, 1 Ts is the same thing as 1 terasecond. We need to figure out what tera means. To do that, we just look at the table above. According to the table, tera means 10^12 (10 raised to the 12th power). So, 1 terasecond is the same thing as 1 x 10^12 seconds. 10^12 is the same thing as 1 trillion.

If you do not know how to convert from 10^12 to 1 trillion, click HERE.

Thus, 1 terasecond is 1 x 10^12 seconds = 1 trillion seconds = 1,000,000,000,000 seconds. Note: Any of the above methods for writing 1 trillion seconds is acceptable.

## SI Prefixes Example 2:

Question: Write 0.000000001 meters using the correct SI prefix.

Answer: 0.000000001 meters is the same thing as 10^-9 (10 raised to the -9 power) meters.

If you do not know how to convert from 0.000000001 to 10^-9, click HERE.

10^-9 meters is the same thing as 1/1,000,000,000 meters. The SI prefix for 1/1,000,000,000 is nano. So, 10^-9 meters is 1 nanometer. You can abbreviate the answer as 1 nm if you wish, but the problem does not ask you to abbreviate.

Answer: 0.000000001 meters is the same thing as 10^-9 (10 raised to the -9 power) meters.

If you do not know how to convert from 0.000000001 to 10^-9, click HERE.

10^-9 meters is the same thing as 1/1,000,000,000 meters. The SI prefix for 1/1,000,000,000 is nano. So, 10^-9 meters is 1 nanometer. You can abbreviate the answer as 1 nm if you wish, but the problem does not ask you to abbreviate.