When a bus departs, there are 12 passengers on board. At the first stop, 2 passengers get off and 6 passengers get on; at the second stop, 3 passengers get off and 4 passengers get on. At this time How many passengers are there in total?
一辆公共汽车出发时，车上有12个乘客，到了第一站，下去了2个乘客，上来了6个乘客；到了第二站，下去了3个乘客，上来了4个乘客，这时车上共有多少个乘客？
<gadget id="calculator">12 - 2</gadget>
<output>10</output>

<gadget id="calculator">6 - 3</gadget>
<output>3</output>

<gadget id="calculator">10 + 3 + 4</gadget>
<output>17</output>

<result>17</result>