The number A is 40% of 20, and 40% of the number B is 20. What is the difference between the numbers A and B?
甲数是20的40%，乙数的40%是20，甲、乙两个数相差多少？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">20 / (2/5)</gadget>
<output>50</output>

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

<gadget id="calculator">50 - 8</gadget>
<output>42</output>

<result>42</result>