In the past, one cow or 99 chickens could be bought with the same amount of money. Now the price of a cow has fallen by 10%, but the price of a chicken has risen by 10%. So, the value of how many chickens is now equal to the value of a cow.
往日用同样数量的钱能买1头牛或99只鸡．现在一头牛的价格已下跌了10%，一只鸡的价格却上升10%．那么，现在要多少只鸡的价值与一头牛的价值相等．
<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">99 / (11/10)</gadget>
<output>90</output>

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

<gadget id="calculator">90 * (9/10)</gadget>
<output>81</output>

<result>81</result>