There are 1000 milliliters to one liter, and 10 deciliters to a liter, so there are 100 milliliters to a deciliter. This means that in 357 milliliters, there are 3.57 deciliters.

There are 50 deciliters in 5 liters, because there are 10 deciliters to one liter. Just remember deci means 10 in roots of words and you shouldn't forget it.