Lao Li has a house worth 90,000 yuan. He sold it to Xiao Zhang with a 10% price increase. After a while, he bought it back for 120,000 yuan. Later, he sold it with a 10% price increase. Lao Li bought and sold one after another. On the whole, To make money or to lose money? How much did you earn or lose?
老李有一幢住房价值9万元，他加价10%卖给了小张，过了一段时间又以12万元买回，后来又加价10%卖出，老李前后买卖，从整体上看，是赚钱还是赔钱？赚或赔了多少元？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">12 * (1/10)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(9/10) + (6/5)</gadget>
<output>21/10 = around 2.1</output>

<result>21/10 = around 2.1</result>