How many degrees does the hour hand rotate from 3:00 to 6:00?
从3：00到6：00，时针旋转了多少度．
<gadget id="calculator">6 - 3</gadget>
<output>3</output>

<gadget id="calculator">360 / 12</gadget>
<output>30</output>

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

<result>90</result>