The original price of a commodity is 50 yuan, the price is first raised (1/10) and then reduced (1/10), what is the current price?
一件商品原价50元，先提价(1/10)后又降价(1/10)，现价是多少．
<gadget id="calculator">1 / 10</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">50 * (11/10) * (9/10)</gadget>
<output>99/2 = around 49.5</output>

<result>99/2 = around 49.5</result>