There are 400 students in the fifth grade of Guangming Primary School, which is less than the sixth grade (1/9). How many students are there in the sixth grade? what is the correct formula
光明小学五年级有学生400人，比六年级少(1/9)，六年级有多少人？正确的算式是多少
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 - (1/9)</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">400 / (8/9)</gadget>
<output>450</output>

<result>450</result>