At 9 o'clock, the minute hand is 80 degrees behind the hour hand.
9点多少分时，分针落后时针80度．
<gadget id="calculator">9 / 12</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">360 * (3/4)</gadget>
<output>270</output>

<gadget id="calculator">270 - 80</gadget>
<output>190</output>

<gadget id="calculator">360 / 60</gadget>
<output>6</output>

<gadget id="calculator">60 * 12</gadget>
<output>720</output>

<gadget id="calculator">360 / 720</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">6 - (1/2)</gadget>
<output>11/2 = around 5.5</output>

<gadget id="calculator">190 / (11/2)</gadget>
<output>380/11 = around 34.545455</output>

<result>380/11 = around 34.545455</result>