Dajiang Sheet Metal Works produced a total of 558 tons of sheet metal in July and August this year. How many tons per day was produced on average in these two months?
大江板材厂今年七、八两个月一共生产板材558吨．这两个月平均每天生产多少吨？
<gadget id="calculator">31 + 31</gadget>
<output>62</output>

<gadget id="calculator">558 / 62</gadget>
<output>9</output>

<result>9</result>