A piece of wood, after sawing off (5/7), there is still 14 meters left, how long is this piece of wood originally?
一根木头，锯掉它的(5/7)后，还剩14米，这根木头原来长多少．
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">14 / (2/7)</gadget>
<output>49</output>

<result>49</result>