There are 280 boxes of pears and 450 boxes of apples, 245 boxes have been shipped, how many boxes are left?
有280箱梨和450箱苹果，已经运走了245箱，还剩多少箱没有运走？
<gadget id="calculator">450 - 245</gadget>
<output>205</output>

<gadget id="calculator">280 + 205</gadget>
<output>485</output>

<result>485</result>