The school bought 450 prizes and distributed them to 7 classes, leaving 30 prizes. How many prizes are there on average per class?
学校买了450份奖品，分给7个班，还剩下30份．平均每班分的奖品多少份？
<gadget id="calculator">450 - 30</gadget>
<output>420</output>

<gadget id="calculator">420 / 7</gadget>
<output>60</output>

<result>60</result>