The school canteen shipped 10 tons of coal, and after using it for a quarter, there are still 2.5 tons left. How many tons of coal are burned on average every month?
学校食堂运来10吨煤，用了一季度后，还剩2.5吨，平均每月烧多少吨煤？
<gadget id="calculator">10 - 2.5</gadget>
<output>7.5</output>

<gadget id="calculator">7.5 / 3</gadget>
<output>2.5</output>

<result>2.5</result>