The volume of each celluloid die is (.25 x .25 x .25) = 0.015625 cubic inch.
To manufacture 24,000 of them, you need to start with at least
(24,000) x (0.015625) = 375 cubic inches.
I don't know how celluloid is sold, so you should also keep in mind that
375 cubic inches = about 207.8 fluid ounces, or about 6.5 quarts.
I'm sure a bit more than that was used in the manufacture, since
there's always some wasted, spilled, or trimmed off of the edges.