From 4:00 am to 4:30 am on the same day, how many degrees did the minute hand rotate?
从同一天的早上4：00到早上4：30，分针旋转了多少°．
<gadget id="calculator">360 / 60</gadget>
<output>6</output>

<gadget id="calculator">6 * 30</gadget>
<output>180</output>

<result>180</result>