For one batch of cookies you'll need 1/2 cup of sugar. 8 batches of cookies is 8 times the amount of batches of one batch of cookies. So, if the amount of batches is multiplied by 8, then we need to multiply the amount of sugar by 8 as well:
1/2 * 8 = 8/2 = 4/1 = 4
4 cups of white sugar are needed for 8 batches of cookies.
