In one exam, Xiao Ming scored 86 points in Chinese and 90 points in English, and now he has to take mathematics. He wants to strive for an average of at least 90 points in the three subjects. So what is the minimum score for his mathematics score?
一次考试中，小明语文得了86分，英语得了90分，现在还要考数学，他想争取三科平均至少为90分，那么他的数学成绩至少要考多少分？
<gadget id="calculator">90 * 3</gadget>
<output>270</output>

<gadget id="calculator">270 - 86 - 90</gadget>
<output>94</output>

<result>94</result>