During the New Year's Day, Heyi Shopping Mall held a promotional activity. Buy a carton of milk and get a free carton. There are a total of 52 people in Class 5. If you buy 4 cartons, you will get one carton per person. How many cartons of milk are there in each carton.
元旦期间，合益商场搞优惠活动，买一箱牛奶送一盒，五1班一共52人，如果买4箱，正好每人一盒，每箱牛奶有多少盒．
<gadget id="calculator">52 - 4</gadget>
<output>48</output>

<gadget id="calculator">48 / 4</gadget>
<output>12</output>

<result>12</result>