The number A is 18, and the number B is 40. What percentage of the number A is the number B?
甲数是18，乙数是40，甲数是乙数的百分之几？
<gadget id="calculator">18 / 40</gadget>
<output>9/20 = around 0.45</output>

<result>9/20 = around 0.45</result>