Xiao Ming reads a 240-page book. He reads (1/4) of the whole book in the first week, and (1/3) of the whole book in the second week. How many pages of this book are left unread?
小明看一本240页的书，第一周看了全书的(1/4)，第二周看了全书的(1/3)，这本书还有多少页没看？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/4) + (1/3)</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">1 - (7/12)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">240 * (5/12)</gadget>
<output>100</output>

<result>100</result>