An oil mill extracts 405 tons of oil in the first quarter and 465 tons in the second quarter. How many tons of oil does this oil mill extract per month on average in the first and second quarters?
一个榨油厂第一季度榨油405吨，第二季度榨油465吨．这个榨油厂第一、二季度平均每月榨油多少吨？
<gadget id="calculator">405 + 465</gadget>
<output>870</output>

<gadget id="calculator">870 / 6</gadget>
<output>145</output>

<result>145</result>