If only half as much milk is used each day, after how many days will more milk need to be purchased

You might need to purchase some because you're only getting half each day you know going to have a gallon like those big ones you don't need to purchase any because you have you need like a half every day so you're not going to run out of milk so you only would buy one milk in two weeks on one week because you're getting one half every day

You will never need to purchase more milk because if you're only taking half each time you will never finish it.