There are 20 good students in the fifth grade, which is (2/9) of the total number of fifth grade students. The number of students in the fifth grade accounts for (1/5) of the whole school. How many students are there in the whole school?
五年级有三好学生20人，是五年级学生总数的(2/9)．五年级学生人数占全校人数的(1/5)，全校有学生多少人？
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">20 / (2/9) / (1/5)</gadget>
<output>450</output>

<result>450</result>