Answer: The mass of sugar that the bar contains is 9815 milligrams.
Step-by-step explanation:
We are given:
Mass of milk chocolate bar = 15.630 g
Mass of sugar in it = 9.815 g
Converting the mass from grams to milligrams, we use the conversion factor:
1 g = 1000 mg
So,

Hence, the mass of sugar that the bar contains is 9815 milligrams.