Use a rope to measure the height of the bridge, fold the rope 4 times on the bridge and hang it to the water surface, the remaining 3 meters; cut the rope 6 meters, after 3 folds, the remaining 4 meters. How many meters is the height of the bridge?
用绳子量桥高，在桥上将绳子4折垂至水面，余3米；把绳子剪去6米，3折后，余4米．桥高是多少米？
<gadget id="calculator">6 / 3</gadget>
<output>2</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

<gadget id="calculator">(1/3) - (1/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">3 / (1/12) / 4</gadget>
<output>9</output>

<gadget id="calculator">9 - 3</gadget>
<output>6</output>

<result>6</result>