A certain boiler room originally planned to burn 480 tons of coal a month (calculated on the basis of 30 days), but actually burned 4 tons less than the original plan every day. How many days can the coal that was originally planned to be burned for a month actually be burned?
某锅炉房，原计划一个月(按30天计算)烧煤480吨，实际每天比原计划少烧4吨，这样原计划烧一个月的煤实际可以烧多少天？
<gadget id="calculator">480 / 30</gadget>
<output>16</output>

<gadget id="calculator">16 - 4</gadget>
<output>12</output>

<gadget id="calculator">480 / 12</gadget>
<output>40</output>

<result>40</result>