How much does the hour hand rotate around the center of the clock face from 12:00 to 15:00.
时针从12：00走到15：00是围绕钟面中心旋转多少．
<gadget id="calculator">360 / 60</gadget>
<output>6</output>

<gadget id="calculator">6 * 15</gadget>
<output>90</output>

<result>90</result>