At 7:00, the minute hand is 45 degrees behind the hour hand.
7点多少分的时候，分针落后时针45度．
<gadget id="calculator">30 * 7</gadget>
<output>210</output>

<gadget id="calculator">210 - 45</gadget>
<output>165</output>

<gadget id="calculator">6 - 0.5</gadget>
<output>5.5</output>

<gadget id="calculator">165 / 5.5</gadget>
<output>30</output>

<result>30</result>