Xiao Ming reads a literary masterpiece, and plans to read 20 pages a day, which can be finished in 5 days. If Xiao Ming actually reads 25 pages a day, how many days can he actually finish reading? (Solve with ratio)
小明读一本文学名著，计划每天读20页，5天可以读完．如果小明实际每天读25页，实际只要多少天就可以读完？(用比例解)
<gadget id="calculator">20 * 5</gadget>
<output>100</output>

<gadget id="calculator">100 / 25</gadget>
<output>4</output>

<result>4</result>