Wang Xiaohong read a 300-page story book, read (1/3) of the book on the first day, and read the whole book (2/5) on the second day. How many pages are left unread?
王晓红读一本300页的故事书，第一天读了这本书的(1/3)，第二天又读了全书的(2/5)．还剩下多少页没读？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/3) - (2/5)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">300 * (4/15)</gadget>
<output>80</output>

<result>80</result>