After transferring out the students from Class 1 of 6 years (1/10), it happens to be equal to the number of Class 2 of 6 years. The number of Class 2 of 6 years is the original number of Class 1
把六年一班的人调出(1/10)后，刚好与六年二班人数相等，六年二班人数是原来六年一班的多少
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>