From 12:00 to 3:00 on the clock, how many degrees does the hour hand rotate clockwise?
钟表上从12：00到3：00，时针顺时针旋转多少度．
<gadget id="calculator">360 / 12</gadget>
<output>30</output>

<gadget id="calculator">30 * 3</gadget>
<output>90</output>

<result>90</result>