# Why is there no prefix for 10^5,10^-5 and 10^4 and 10^-4?

• B
• ppppparker

#### ppppparker

or, why was one never adopted?

Just a convention? 10^3 a time?

ppppparker said:
or, why was one never adopted?
Myria for ##10^4## and dimi for ##10^{-4}## have been in use in France until the middle of the 20th century.
Today we use potentials of ##10## until ##1000## and then potentials of ##1000## which makes sense to cover the different orders we face. For everyday life we still have the small ones plus some special terms like hectares or acres.

## 1. Why are there no prefixes for 10^5 and 10^-5?

The International System of Units (SI) only has prefixes for powers of 10 that are multiples of 3. Since 10^5 and 10^-5 are not multiples of 3, they do not have corresponding prefixes.

## 2. Why isn't there a prefix for 10^4 and 10^-4?

The SI system also does not have prefixes for powers of 10 that are less than 1. Therefore, there is no prefix for 10^4 and 10^-4.

## 3. Can't we just use existing prefixes for 10^5 and 10^-5?

While some people may use existing prefixes like "hecto" or "micro" to represent 10^5 and 10^-5, this is not officially recognized in the SI system. It is important to use standard units and prefixes in scientific communication.

## 4. Are there any alternative ways to represent 10^5 and 10^-5?

Yes, instead of using a prefix, we can use scientific notation to represent 10^5 and 10^-5. For example, 10^5 can be written as 100,000 and 10^-5 can be written as 0.00001.

## 5. Why do we need prefixes for powers of 10?

Prefixed units make it easier to express very large or very small numbers in a compact and standardized way. This is especially useful in scientific and technical fields where we often deal with numbers that are much larger or smaller than 1.