40% of a number is 8, what is 45% of this number?
一个数的40%是8，这个数的45%是多少．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">8 / (2/5)</gadget>
<output>20</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

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

<result>9</result>