A TV set is sold in a department store. If it is sold at 10% off the price, it is 210 yuan cheaper than the price. How much is the price of the TV?
百货商场出售一台电视机，如果按定价的九折卖出，比定价便宜210元，电视机的定价是多少元？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">210 / (1/10)</gadget>
<output>2_100</output>

<result>2_100</result>