20 is 4 more than (2/5) of a number, find this number.
20比一个数的(2/5)多4，求这个数．
<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">16 / (2/5)</gadget>
<output>40</output>

<result>40</result>