National Day, leather shoe store promotion, sold 99 pairs of leather shoes in the morning, 10% more than in the afternoon, how many pairs were sold in the afternoon?
国庆节，皮鞋店促销活动，上午卖出皮鞋99双，比下午多卖10%，下午卖了多少双？
<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>

<result>90</result>