There are 720 students in the first grade of Yucai Middle School, and the number of students in the first grade is less than the number of students in the second grade (1/5). How many students are there in the second grade? (column equation solution)
育才中学初一年段有720人，初一段的学生人数比初二段学生人数少(1/5)．初二共有学生多少人？(列方程解答)
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">720 / (4/5)</gadget>
<output>900</output>

<result>900</result>