If you subtract 9 from the numerator of (12/16), how much should the denominator be multiplied to keep the fraction constant?
如果把(12/16)的分子减去9，要使分数的大小不变，分母应乘以多少
<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>