For a novel, Xiao Ming read (1/3) of the whole book on the first day, and (1/4) of the whole book on the second day, and left some of the whole book unread.
一本小说，小明第一天看了全书的(1/3)，第二天看了全书的(1/4)，还剩下全书的多少没有看．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

<gadget id="calculator">1 - (1/3) - (1/4)</gadget>
<output>5/12 = around 0.416667</output>

<result>5/12 = around 0.416667</result>