(2/5)-(1/4)-(1/10)=how much.
(2/5)-(1/4)-(1/10)=多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(2/5) - (1/4) - (1/10)</gadget>
<output>1/20 = around 0.05</output>

<result>1/20 = around 0.05</result>