A number is equal to (1/5) after reducing its (1/5), what is this number? How many formulas
一个数减少它的(1/5)后等于(1/5)，这个数是多少？算式多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(1/5) / (4/5)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>