The bus from Nanjing to Suzhou departs every 30 minutes. The first bus departs at 6:00 a.m. Xiao Ming wants to take the bus that leaves at 9:00 a.m., which bus should it be?
从南京到苏州的汽车每30分钟开出一班，早晨6时开出第一班，小明要坐第9时开出的车，应该是第几班车？
<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<gadget id="calculator">3 / 0.5</gadget>
<output>6</output>

<gadget id="calculator">6 + 1</gadget>
<output>7</output>

<result>7</result>