The bus travels from place A to place B. It travels the whole distance (1/4) in the first hour, and the rest (2/9) in the second hour. How much of the whole journey is left?
客车从甲地开往乙地，第一小时行了全程的(1/4)，第二小时行了余下的(2/9)，还剩下全程的多少没行．
<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">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">(3/4) * (2/9)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/4) - (1/6)</gadget>
<output>7/12 = around 0.583333</output>

<result>7/12 = around 0.583333</result>