6 red discs account for the whole (1/3), and add 6 more red discs, then how much red discs account for the whole.
6个红圆片占整体的(1/3)，再增加6个红圆片，这时红圆片占整体的多少．
<gadget id="calculator">6 + 6</gadget>
<output>12</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">6 / (1/3)</gadget>
<output>18</output>

<gadget id="calculator">18 + 6</gadget>
<output>24</output>

<gadget id="calculator">12 / 24</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>