Before the Nanjing Yangtze River Bridge was built, it took (25/12) hours to cross the Yangtze River by train, but now it only takes (1/4) hour to cross the bridge. How many hours does it save to cross the river by train than by ferry?
南京长江大桥建成以前，火车乘轮渡过长江，需要(25/12)小时，现在从大桥通过只用(1/4)小时．现在火车过江比乘轮渡节省多少小时？
<gadget id="calculator">25 / 12</gadget>
<output>25/12 = around 2.083333</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(25/12) - (1/4)</gadget>
<output>11/6 = around 1.833333</output>

<result>11/6 = around 1.833333</result>