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.
