(4/7) of a number is 8, how much more (1/2) of this number than (3/7) of it.
一个数的(4/7)是8，这个数的(1/2)比它的(3/7)多多少．
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">8 / (4/7)</gadget>
<output>14</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(1/2) - (3/7)</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">14 * (1/14)</gadget>
<output>1</output>

<result>1</result>