The number of students in a certain grade has increased by (1/6) compared to the original one. There are currently 420 students. How many are the original students?
某年级学生比原来增加了(1/6)，现有学生420人，原有学生多少人？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 + (1/6)</gadget>
<output>7/6 = around 1.166667</output>

<gadget id="calculator">420 / (7/6)</gadget>
<output>360</output>

<result>360</result>