There are 650 people on the train, 110 people get off at Shanghai Station, and 250 people get on, how many people are on the train now?
火车上有650人，到上海站下去110人，又上来250人，现在火车上有多少人？
<gadget id="calculator">650 - 110</gadget>
<output>540</output>

<gadget id="calculator">540 + 250</gadget>
<output>790</output>

<result>790</result>