The school bought 4 boxes of books, 80 books in each box, and distributed them to 5 grades on average. How many books are there in each grade?
学校买来4箱图书，每箱80本，平均分给5个年级，平均每个年级多少本．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">80 * (4/5)</gadget>
<output>64</output>

<result>64</result>