There are 5 students participating in the mathematics competition, and the average score of 4 of them is 81.5 points; after adding Li Dong's score, the average score is 84 points, what is Li Dong's score?
有5个同学参加数学竞赛，其中4人的平均成绩是81.5分；加上李冬的分数后平均成绩84分，李冬的成绩是多少分？
<gadget id="calculator">84 * 5</gadget>
<output>420</output>

<gadget id="calculator">81.5 * 4</gadget>
<output>326</output>

<gadget id="calculator">420 - 326</gadget>
<output>94</output>

<result>94</result>