Xiao Ming reads an 80-page story book. He reads 20% of the whole book on the first day and 25% of the whole book on the second day. How many pages are left?
小明看一本80页的故事书，第一天看了全书的20%，第二天看了全书的25%，还剩多少页没看．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/5) - (1/4)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">80 * (11/20)</gadget>
<output>44</output>

<result>44</result>