For a piece of wire, (1/5) meter is used for the first time, and (1/8) meter is used for the second time. How much shorter is this wire than the original?
一根铁丝，第一次用去(1/5)米，第二次用去(1/8)米．这根铁丝比原来短多少米？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/5) + (1/8)</gadget>
<output>13/40 = around 0.325</output>

<result>13/40 = around 0.325</result>