Answer: To make one milkshake, Nathan needs 1/4 tablespoon of vanilla. To find out how much vanilla he needs for 8 milkshakes, we can multiply the amount needed for one milkshake by 8:
Vanilla needed for 1 milkshake = 1/4 tablespoon
Vanilla needed for 8 milkshakes = (1/4 tablespoon) x 8
Multiplying 1/4 by 8 gives:
Vanilla needed for 8 milkshakes = 2 tablespoons
Therefore, Nathan will need 2 tablespoons of vanilla to make 8 milkshakes, assuming he uses 1/4 tablespoon of vanilla for each milkshake.