Obviously reading a 350-page book, I have already read (3/5) of the whole book, how many pages are left?
明明看一本350页的书，已经看了全书的(3/5)，还剩多少页没看？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">350 * (2/5)</gadget>
<output>140</output>

<result>140</result>