There are 48 passengers on a bus, and some people get off after arriving at the station. At this time, there are still 39 passengers on the bus. How many people got off when they arrived at the stop?
一辆公共汽车上有乘客48人，到站后下去一些人，这时公共汽车上还有乘客39人，到站时下去了多少人？
<gadget id="calculator">48 - 39</gadget>
<output>9</output>

<result>9</result>