How much does the hour hand rotate around the center of the clock face to go from 15:00 to 18:00.
时针绕钟面中心旋转多少才能从15：00走到18：00．
<gadget id="calculator">360 / 60</gadget>
<output>6</output>

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

<result>90</result>