Convert Metric Prefixes to Decimal Values

For the sake of making  calculations, a common first step is to convert a measurement with a metric prefix to its decimal equivalent.  So, instead of starting with 1 kΩ, you’d want to start with 1000 Ω.  For this step, just replace the metric prefix with x metric-prefix-decimal-value.  If you are not sure of the metric prefix’s decimal value, just look it up in the table.

Here is another example with 20 ms.  Looking up m in the SI Metric Prefixes table, its decimal value is 0.001.  So, replace m with x 0.001, and then calculate the result.

If you multiply some value by 1, the result is that same value.  For example, 2 kΩ x 1 = 2 kΩ.  The quantity is unchanged.  The faction 1000 / k is also equal to the number 1.  Remember from the SI Metric Prefix chart that kilo = 1000.  So if you start with k = 1000 and divide both sides by k, you get 1000 / k = 1.  Multiplying 2 kΩ by 1 (in the form of 1000/k), the k’s in the numerator and denominator cancel, and the result is 2000 Ω.  It’s still the same value as 2 kΩ, but in this case, without the metric prefix.  

(View full size: muam-multiply-by-one-prefix-to-val.mp4)