For a water pipe, cut off the full length (1/4) for the first time, and cut off the remaining (1/3) for the second time, how much is the total length cut off?
一根水管，第一次截去全长的(1/4)，第二次截去余下的(1/3)，共截去全长的多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(3/4) * (1/3)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) + (1/4)</gadget>
<output>1/2 = around 0.5</output>

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