A canteen burns 340 kilograms of coal per day in the first 10 days of April, and saves 30 kilograms of coal per day in the last 20 days. How many kilograms of coal is burned per day on average this month?
一个食堂在四月份的前10天每天烧煤340千克，后20天中每天比原来节约30千克，这个月平均每天烧煤多少千克？
<gadget id="calculator">340 * 10</gadget>
<output>3_400</output>

<gadget id="calculator">340 - 30</gadget>
<output>310</output>

<gadget id="calculator">310 * 20</gadget>
<output>6_200</output>

<gadget id="calculator">3_400 + 6_200</gadget>
<output>9_600</output>

<gadget id="calculator">10 + 20</gadget>
<output>30</output>

<gadget id="calculator">9_600 / 30</gadget>
<output>320</output>

<result>320</result>