The difference between (1/4) and (1/5) is divided by a number to get 10, what is the number?
(1/4)与(1/5)的差除一个数得10，求这个数是多少？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/20) * 10</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>