I hope the elementary school bought some extracurricular reading materials and distribute them to 4 classes on average. Each class gets 40 books, and there are 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4个班，每班分到40本，还剩下30本．一共买来多少本书？
<gadget id="calculator">40 * 4</gadget>
<output>160</output>

<gadget id="calculator">160 + 30</gadget>
<output>190</output>

<result>190</result>