The price of a certain model of mobile phone after two consecutive price cuts of 10% is equivalent to the original price.
某种型号的手机，连续两次降价10%后的价格相当于原价的多少．
<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">1 * (9/10) * (9/10)</gadget>
<output>81/100 = around 0.81</output>

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