After increasing (1/5) of 50kg, how much is it to decrease (1/5) in kg?
50kg增加它的(1/5)后，再减少(1/5)是多少kg．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">50 * (1/5)</gadget>
<output>10</output>

<gadget id="calculator">10 + 50</gadget>
<output>60</output>

<gadget id="calculator">60 * (1/5)</gadget>
<output>12</output>

<gadget id="calculator">60 - 12</gadget>
<output>48</output>

<result>48</result>