There are 450 students in Yangcun Primary School. The number of students in the lower grades accounts for 60% of the total number of students in the school. It is known that the number of students in the middle grades is in the lower grades (2/5). How many students are there in the middle grades?
杨村小学有学生450人，低年级的学生人数占全校学生人数的60%，已知中年级学生人数是低年级的(2/5)，中年级有学生多少人？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">450 * (3/5) * (2/5)</gadget>
<output>108</output>

<result>108</result>