The average of the four numbers A, B, C, and D is 20. After removing one number, the average of the remaining numbers is 22. What is the removed number?
甲、乙、丙、丁四个数的平均数为20，去掉一个数后，余下数的平均数是22，去掉的数是多少．
<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">22 * 3</gadget>
<output>66</output>

<gadget id="calculator">80 - 66</gadget>
<output>14</output>

<result>14</result>