The students have to do 180 small flags, (5/6) have been done, and ((())/(())) have not been done, how many sides are still left to be done.
同学们要做180面小旗，已经做了(5/6)，还有((())/(()))没做，还有多少面没做．
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 - (5/6)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">180 * (1/6)</gadget>
<output>30</output>

<result>30</result>