A piece of clothing is 40 yuan cheaper after a 10% discount. What is the original price of this piece of clothing?
一件衣服，打九折后便宜了40元，这件衣服原价多少元．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">40 / (1/10)</gadget>
<output>400</output>

<result>400</result>