Xiaohui reads an 80-page book. She reads 3/5 of the whole book on the first day and 25% of the whole book on the second day. How many pages are left?
小慧看一本80页的书，第一天看了全书的(3/5)，第二天看了全书的25%，还剩多少页没看？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">1 - (3/5) - (1/4)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">80 * (3/20)</gadget>
<output>12</output>

<result>12</result>