road is 72 kilometers long, and (1/9) has been traveled, how many kilometers are left to go.
一条公路长72千米，已经走了(1/9)，还剩多少千米没走．
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 - (1/9)</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">72 * (8/9)</gadget>
<output>64</output>

<result>64</result>