Xiao Ming reads a 100-page story book. He reads (1/5) of the book on the first day, and the rest (1/4) on the second day. On the third day, which page should he read?
小明看一本100页的故事书，第一天看了这本书的(1/5)，第二天看了余下的(1/4)，第三天从第几页看起？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">100 * (1/5)</gadget>
<output>20</output>

<gadget id="calculator">100 - 20</gadget>
<output>80</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">80 * (1/4)</gadget>
<output>20</output>

<gadget id="calculator">20 + 20 + 1</gadget>
<output>41</output>

<result>41</result>