There are 220 students in the first grade of Yuhong Primary School, which is 10% more than the second grade. How many students are there in the first and second grades?
育红小学一年级有220人，比二年级多10%，一、二年级共有多少人？
<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">220 / (11/10)</gadget>
<output>200</output>

<gadget id="calculator">200 + 220</gadget>
<output>420</output>

<result>420</result>