For a simple fraction, increase its numerator by 1 to get (2/3), and decrease its numerator by 1 to get (1/2). What is the fraction?
一个最简分数，把它的分子增加1就得到(2/3)，把它的分子减少1就得到(1/2)，这个分数是多少．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<result>7/12 = around 0.583333</result>