Uncle Wang wants to transport 520 boxes of apples to the warehouse. The first truck transports 150 boxes, and the second truck transports 180 boxes. How many boxes are left?
王叔叔要把520箱苹果运到仓库，第一车运走150箱，第二车运走180箱，还有多少箱没有运走？
<gadget id="calculator">520 - 150 - 180</gadget>
<output>190</output>

<result>190</result>