After cutting 28 meters from a piece of wood, there is still (4/7), how many meters is this piece of wood long? Calculation formula: how much.
一段木料截去28米后还剩(4/7)，这段木料长多少米？算式：多少．
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1 - (4/7)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">28 / (3/7)</gadget>
<output>196/3 = around 65.333333</output>

<result>196/3 = around 65.333333</result>