80% of 15 is equal to (2/3) of that number.
15的80%和多少的(2/3)相等．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(4/5) / (2/3)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">15 * (6/5)</gadget>
<output>18</output>

<result>18</result>