40% of a number is 18, what is (4/9) of this number?
一个数的40%是18，这个数的(4/9)是多少．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">18 / (2/5)</gadget>
<output>45</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">45 * (4/9)</gadget>
<output>20</output>

<result>20</result>