304.8 - call it 305.
1 lightyear = 9.46073 * 1018 millimetre. The question WAS about 1 light year, wasn't it?
1 millimeter = 0.1 cm
The units ARE comparable, its just as if you drop a rock on a glass of water, the rock displaces some space and takes up some volume. 1 gram is equal to 1 ml.
10 dm = 1 meter 1000 mm = 1 m 1000 mm = 10 dm 1 mm = 10 / 1000 = .01 dm .
Feet is the plural of foot. 1 foot is 1 foot & 12 inches is one foot