First you’d have to identify what you’re measuring
1. Measurement of volume (liquid) is liters
2. Measurement of distance is meters
3. Measurement of mass is grams
After identifying it and choosing one, you have to pick the prefix you are going to use. Grams, meters, and liters are all bases and you can increase it by following the KHDbdcm scale
Kilo. Hecto. Deka. Base. Deci. Centi. Milli.
And you do it according
For example if you are measuring the distance from one city to another you’ll use kilometers while you’d use centimeters to measure the length of your finger.
