How much does the hour hand on the clock face rotate from 5:30 to 6:00?
钟面上的时针从5：30到6：00旋转了多少．
<gadget id="calculator">360 / 12</gadget>
<output>30</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">30 * (1/2)</gadget>
<output>15</output>

<result>15</result>