The school cafeteria brought 2 tons of coal and planned to burn it for 80 days. 5 kilograms are saved every day due to the improvement of the stove. How many days can this batch of coal be burned?
学校食堂运来2吨煤，计划烧80天．由于改进炉灶，每天节省5千克，这批煤可烧多少天？
<gadget id="calculator">1_000 / 80</gadget>
<output>25/2 = around 12.5</output>

<gadget id="calculator">2 * (25/2)</gadget>
<output>25</output>

<gadget id="calculator">25 - 5</gadget>
<output>20</output>

<gadget id="calculator">1_000 / 20</gadget>
<output>50</output>

<gadget id="calculator">2 * 50</gadget>
<output>100</output>

<result>100</result>