Jill went to the grocery store and spent $50 to buy food. She gave half of the food to Sue. Sue asks Jill: "How much do I owe you for the groceries?" Jill answers: I spent $50 and I gave half of the food to you. You owe me $25.
Groceries means food that you buy to prepare for yourself (not restaurant food). How much money should I give you to repay you for the money you spent buying food for me from the store?