Help wrote:How do I convert .04mg/L to mg/dL
All you need to know is what a deciliter is (0.1 L). Since 10 dL = 1 L,
0.04 mg/dL x 10 dL/1 L = 0.4 mg/L
If you know the conversion factor for each unit involved, all conversion calculations can be handled by a chain calculation of this type; notice that the unwanted unit (dL) cancels out.
In metric, you can do these in your head by moving decimal points. In "english" units, it is a nightmare and requires a calculator.