Prefixes and Conversion

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Prefixes

Very large and small measurements can be troublesome to work with, for example, a metre would be too small to describe the perimeter of St. Lucia or a kilogram would be too large to describe the mass of a grain of rice. We can use scientific notation to simplify these measurements and we use specific scientific notation (usually multiples of ten to the power of three) which are represented by letters (symbols) that we call prefixes. Table 1 below shows some common prefixes. 

Conversion

Conversion is the process of representing a measurement from a given prefix to another. 

Note: 
There are many ways to convert!
The following two (2) methods, in my opinion are the easiest to understand and follow.  

Types of Conversion:

1. Unit Conversion
2. Prefix Subtraction

Unit Conversion

This method of conversion works on the premise that 'if you know for one, then you can find for any by multiplication'. If this statement is true, then we need to find for one unit of the given measurement and equate it to its equivalent in the unit we require.

What is a unit measurement?
A unit measurement is a measurement with a value of one (1), for example: 1 cm, 1 kg, 1 A, 1 s, 1 K, etc.

How is Unit Conversion done:

1. State the unit equality. If you are converting from a Multiple or Base Unit to a Sub-multiple, the unit measurement is placed on the right hand side of the equal sign and from a Sub-multiple to a  Multiple or Base Unit , the unit measurement is placed on the left hand side of the equal sign. 
2. Divide by the factor to get the unit on the right hand side of the equal sign.
3. Multiply by the given measurement.
4. Simplify the answer as desired, which may be a fraction, decimal or scientific notation.   

Example 4 and 5 require two steps for simplicity. With enough practice you will be able to convert in one step or by just looking at the question 😉!

Prefix Subtraction

This method is achieved by subtracting the indices (powers) of the scientific notation of the required prefix from the given measurement and multiply the result to the measurement.

How is Prefix Subtraction done:

1. State the scientific notation for each prefix.
2. Subtract the indices (powers) of the two scientific notations.
3. Multiply the decimal value of the result to the measurement.
4. Simplify the answer using scientific notation if required.   

Empowerment Through Practice!

Test your knowledge and Attempt Quiz 3