The numerator of (15/24) is reduced to the original (1/3), how much should be subtracted from the denominator to keep the size of the fraction unchanged.
(15/24)的分子缩小为原来的(1/3)，要使分数的大小不变，分母应当减去多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">24 * (2/3)</gadget>
<output>16</output>

<result>16</result>