The school bought 800 new books and distributed them to 4 grades on average, with 4 classes in each grade. How many books per class on average?
学校买来800本新书，平均分给4个年级，每个年级4个班，平均每班多少本？
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">800 / 16</gadget>
<output>50</output>

<result>50</result>