Xiao Ming reads a 180-page book, and has read (2/3) of the whole book. How many pages are left unread?
小明读一本180页的书，已读了全书的(2/3)，还剩下多少页没读？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">180 * (1/3)</gadget>
<output>60</output>

<result>60</result>