A store opens at 9:00 am and closes at 6:00 pm. The total sales for the whole day is 639 yuan. How much is the average hourly sales?
某商店上午9：00开始营业，下午6：00停止营业，全天共销售639元，平均每小时销售多少钱？
<gadget id="calculator">639 / 9</gadget>
<output>71</output>

<result>71</result>