For a jacket, the merchant first increases the price by 10%, and then sells it at a 10% discount. The current price of this jacket is 99 yuan. How much is the original price of this jacket?
一件上衣，商家先提价10%，再降价10%出售，这件上衣现价是99元，问这件上衣原价是多少元？
<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">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(11/10) * (9/10)</gadget>
<output>99/100 = around 0.99</output>

<gadget id="calculator">99 / (99/100)</gadget>
<output>100</output>

<result>100</result>