Xiao Ming's average score in the first three units of mathematics is 90 points. Among them, the first unit is 88 points, the second unit is 92 points, and the third unit is how many points.
小明同学数学前3个单元的平均分是90分．其中第一单元是88分，第二单元是92分，第三单元是多少分．
<gadget id="calculator">90 * 3</gadget>
<output>270</output>

<gadget id="calculator">270 - 88 - 92</gadget>
<output>90</output>

<result>90</result>