A book has 60 pages, 60% of which have been read, how many pages have not been read.
一本书60页，读了60%，多少页没有读．
<gadget id="calculator">60 / 100</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">60 * (2/5)</gadget>
<output>24</output>

<result>24</result>