In 4:X=6:5, if 4 increases by 16, how much should X be increased, and the ratio is still valid.
在4：X=6：5中，若4增加16，则X应增加多少，比例仍成立．
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">20 * (5/6)</gadget>
<output>50/3 = around 16.666667</output>

<gadget id="calculator">6 / 5</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">4 / (6/5)</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">(50/3) - (10/3)</gadget>
<output>40/3 = around 13.333333</output>

<result>40/3 = around 13.333333</result>