During the summer camp, 38 students visited the popular science exhibition. The ticket office stipulates that tickets for one person are 10 yuan, and tickets for ten people are 7 yuan each. How much do they buy tickets at least?
在夏令营活动中，38位学生参观科普展览．售票处规定，门票一人券10元，十人券每张7元．他们购买门票至少要多少元．
<gadget id="calculator">7 * 30</gadget>
<output>210</output>

<gadget id="calculator">10 * 8</gadget>
<output>80</output>

<gadget id="calculator">210 + 80</gadget>
<output>290</output>

<result>290</result>