If the price of a product is first increased by 10%, and then the price is reduced by 10%, how much is the final price of this product lower than the original price?
一件商品先涨价10%，后降价10%，这件商品最后价格比原价降了多少
<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">1 - (99/100)</gadget>
<output>1/100 = around 0.01</output>

<result>1/100 = around 0.01</result>