If a pile of coal burns 6 tons per day, it can be burned for 40 days. If it burns less than 1.2 tons per day, how many more days can it be burned?
一堆煤每天烧6吨，可以烧40天，如每天少烧1.2吨，可以多烧多少天？
<gadget id="calculator">6 * 40</gadget>
<output>240</output>

<gadget id="calculator">6 - 1.2</gadget>
<output>4.8</output>

<gadget id="calculator">240 / 4.8</gadget>
<output>50</output>

<gadget id="calculator">50 - 40</gadget>
<output>10</output>

<result>10</result>