When x=how much, 0.6:x and (2/5):2 can form a ratio.
当x=多少时，0.6：x和(2/5)：2能组成比例．
<gadget id="calculator">0.6 * 2</gadget>
<output>1.2</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<result>3</result>