Hope primary school bought some extra-curricular reading materials and distributed them to 12 classes on average, each class got 40 books, and there were 30 books left. How many books did you buy in total?
希望小学买来一些课外读物，平均分给12个班，每班分到40本，还剩下30本．一共买来多少本书？
<gadget id="calculator">480 + 12</gadget>
<output>492</output>

<result>492</result>