The average score of Xiao Ming's three unit tests is 96 points. The first and third test scores are 100 points and 98 points respectively. What is the second test score?
小明三次的单元测试的平均成绩是96分，第一次和第三次的成绩分别是100分和98分，第二次的成绩是多少分？
<gadget id="calculator">96 * 3</gadget>
<output>288</output>

<gadget id="calculator">100 + 98</gadget>
<output>198</output>

<gadget id="calculator">288 - 198</gadget>
<output>90</output>

<result>90</result>