A book with 400 pages, Xiaoli planned to finish it in 8 days, but actually read 10 pages less every day, how many days did she actually finish it?
一本书400页，小丽计划8天看完，实际每天少看10页，实际几天看完？
<gadget id="calculator">400 / 8</gadget>
<output>50</output>

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

<gadget id="calculator">400 / 40</gadget>
<output>10</output>

<result>10</result>