Regardless of what is being measured, 8 oz is equal to 1 cup.
True, if it's fluid ounces. If ounces are weight, it's not the same - a cup of lead and a cup of sugar can't both weigh 8 oz. This is yet another problem with using these archaic measurements rather than metric.
So first determine whether the 8 oz means volume (then it's a cup) or weight (use a kitchen scale).
how many cups are in a one pound box of confectioners sugar?
16 ounces
4
approximately 500 grams
That is 3.628 cups of sugar
About 3 cups
half cup of caster sugar will be present in 4oz caster sugar.
One cup is 8 oz. So 50 cups is 25 pounds.
There is approximately 2 cups of lactose sugar in one pound of sugar. However, there is 3 3/4 cups of confectioners sugar in one pound.
Approximately 40 ounces.
2 cups.
1 pound = 16 ounces - whether of sugar or not.