How would you convert a mass in centigrams to a mass in milligrams? ?

First let's start with the relationship between grams and centigrams and grams and milligrams.

1 gram = 100 centigrams
1 gram = 1000 milligrams

Because these two equations are equal, we can rewrite our equation as 100 centigrams = 1000 milligrams.

Now we divide by 100 to simplify our equation to 1 centigram = 10 milligrams.

With this simplified equation we see that we multiply the number of centigrams by 10 to find the equal number of milligrams.