Okay, so, Colby made 9 batches, right? And each batch contained 1/4 quart of grape juice. To find how much grape juice he used for the 9 batches, you have to multiply 1/4 and 9. 1/4*9 = 9/4. Simplified: 9/4 turns into 2 1/4. Colby used 2 1/4 quarts of grape juice.