A book has 120 pages, Xiaojun has read (3/4), how many pages are left?
一本书有120页，小军已看了(3/4)，还有多少页没看？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">120 * (1/4)</gadget>
<output>30</output>

<result>30</result>