How much is 4kg after adding (1/4) of it?
4kg增加它的(1/4)后是多少kg．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">4 * (5/4)</gadget>
<output>5</output>

<result>5</result>