There are 820 students in our school this year, an increase of 10% over last year. How many people were there last year? what is the formula
我校今年有学生820人，比去年增加了10%．去年有多少人？算式是多少
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 + (1/10)</gadget>
<output>11/10 = around 1.1</output>

<gadget id="calculator">820 / (11/10)</gadget>
<output>8_200/11 = around 745.454545</output>

<result>8_200/11 = around 745.454545</result>