Add a number to the numerator of (8/12) and subtract the same number from the denominator to get the simplest fraction (3/2). What is this number?
(8/12)的分子加上一个数，分母减去同一个数后得到的最简分数是(3/2)．这个数是多少．
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) * 12</gadget>
<output>18</output>

<gadget id="calculator">18 - 8</gadget>
<output>10</output>

<gadget id="calculator">1 + (3/2)</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">10 / (5/2)</gadget>
<output>4</output>

<result>4</result>