How much less (2/5) ton is than (1/2) ton.
(2/5)吨比(1/2)吨少多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) / (1/2)</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>