There is a batch of coal, originally planned to burn 400 kg per day, which can be used for 15 days. Actually, it took 5 days longer than planned. How many kilograms did you actually burn less per day than planned?
有一批煤，原计划每天烧400千克，这样可以用15天．实际比计划多烧了5天．实际每天比计划少烧多少千克？
<gadget id="calculator">400 * 15</gadget>
<output>6_000</output>

<gadget id="calculator">15 + 5</gadget>
<output>20</output>

<gadget id="calculator">6_000 / 20</gadget>
<output>300</output>

<gadget id="calculator">400 - 300</gadget>
<output>100</output>

<result>100</result>