Pretty, Pretty Proteins

How much protein should we eat?
Say I weighed 100 pounds. (I wish.) Every day I should eat 1 gram of protein for every 2 pounds I weigh. So I need 50 g protein:
100 pounds/2 = 50A peanut butter sandwich has about 8 g of protein. How many sandwiches should I eat to get all 50 g for the day?