pile of coal was originally planned to burn 50 kilograms per day, which can be burned for 32 days. It actually burned for 40 days. How many kilograms were burned less than the original plan?
一堆煤原计划每天烧50千克，可以烧32天．实际烧了40天，实际每天比原计划每天少烧多少千克？
<gadget id="calculator">32 / 40</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">50 * (4/5)</gadget>
<output>40</output>

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

<result>10</result>