20 tons increased (1/5), how many tons is it now?
20吨增加了(1/5)，现在是多少吨．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">20 * (1/5)</gadget>
<output>4</output>

<gadget id="calculator">20 + 4</gadget>
<output>24</output>

<result>24</result>