From 4 o'clock to 4:30, how many degrees did the minute hand turn on the clock face?
从4时到4时半，钟面上分针转过了多少度．
<gadget id="calculator">360 / 60</gadget>
<output>6</output>

<gadget id="calculator">30 * 6</gadget>
<output>180</output>

<result>180</result>