A book has 250 pages in total. Qiqi read 20% of the book on the first day and the remaining 20% on the second day. How many pages did he read less on the second day than on the first day?
一本书共250页，齐齐第一天看了全书的20%，第二天看了余下的20%，第二天比第一天少看多少页？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">250 * (1/5)</gadget>
<output>50</output>

<gadget id="calculator">250 - 50</gadget>
<output>200</output>

<gadget id="calculator">200 * (1/5)</gadget>
<output>40</output>

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

<result>10</result>