If I give you a 5 and want only 1 sandwich, you can't reject my money, neither force me to buy 5 sandwiches.
If you give me a 5 you are purchasing 5 sandwiches.
Edit: nobody is forcing you to hand me a 5
If I give you a 5 and want only 1 sandwich, you can't reject my money, neither force me to buy 5 sandwiches.
If you give me a 5 you are purchasing 5 sandwiches.
Edit: nobody is forcing you to hand me a 5