The number of students in Xiangyang Primary School this year has decreased by 10% compared to last year, and it is estimated that next year will be reduced by 10% compared to this year. What is the estimated number of students next year compared to last year?
向阳小学今年的学生人数比去年减少10%，估计明年比今年还要减少10%，估计明年的学生人数是去年的多少
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">(9/10) * (9/10)</gadget>
<output>81/100 = around 0.81</output>

<result>81/100 = around 0.81</result>