Yuying Primary School has 20% more students in the lower grades than the middle grades, and 20% more middle-grade students than the upper grades. There are 180 students in the lower grades, and how many students are there in the upper grades?
育英小学低年级的学生比中年级的多20%，中年级学生比高年级学生多20%，低年级有学生180人，高年级有学生多少人？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">180 / (6/5) / (6/5)</gadget>
<output>125</output>

<result>125</result>