After the price of a household appliance has been reduced by 10% twice in a row, the current price is equivalent to the price before the price reduction.
一种家用电器连续两次降价10%后，现在的售价相当于降价前的多少．
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">(9/10) * (9/10)</gadget>
<output>81/100 = around 0.81</output>

<result>81/100 = around 0.81</result>