This picture shows how to convert MASS units if you look at the table and you want to convert.
eg;3 kilograms to a gram follow the chart and times it by 1000 and the answer will be 3000.
You could do it the other way too converting grams to kilograms.
eg; 3000 grams turns into 3 kilograms
this works because a kilogram is 1000 grams.