steel bar is 18 meters long, (1/3) of the full length is used for the first time, and the remaining (1/4) is used for the second time, find the length of the remaining part.
一根钢筋长18米，第一次用去了全长的(1/3)，第二次用去了余下的(1/4)，求剩余部分的长度．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<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">18 * (2/3) * (3/4)</gadget>
<output>9</output>

<result>9</result>