piece of iron wire, after (2/3) is used up, there is still (3/4) meter left, how many meters is the original length of this iron wire?
一根铁丝，用去(2/3)后还剩(3/4)米，这根铁丝原来长多少米？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(3/4) / (1/3)</gadget>
<output>9/4 = around 2.25</output>

<result>9/4 = around 2.25</result>