A worker starts work at 8:00 a.m. and finishes at 4:00 p.m. with a two-hour break at noon. A total of 480 parts are produced throughout the day, how many parts are produced per hour on average?
一个工人上午8时开始工作，到下午4时收工，中午休息两小时．全天共生产480个零件，平均每小时生产多少个零件？
<gadget id="calculator">4 - 8 - 2</gadget>
<output>-6</output>

<gadget id="calculator">12 + (-6)</gadget>
<output>6</output>

<gadget id="calculator">480 / 6</gadget>
<output>80</output>

<result>80</result>