The supermarket shipped 12 boxes of milk, each with 24 boxes, and put them on 4 shelves. How many cartons of milk are on average on each shelf?
超市运来12箱牛奶，每箱24盒，放在4个货架上．平均每个货架上放多少盒牛奶？
<gadget id="calculator">24 / 4</gadget>
<output>6</output>

<gadget id="calculator">12 * 6</gadget>
<output>72</output>

<result>72</result>