what does 1/4th of a pound of sugar equal in cups?
It would approximately be one cup. This is because one pound of unsifted powdered sugar is equal to about 4 cups of the same sugar. Hence you will multiply the by the 4 cups to get the number of cups equivalent to the pounds given.
About 1 cup, I'd guess.
This is weight and volume. I can solve this if you can tell me what a grain of sugar weighs and its dimensions.
About 1 cup