The original price of a piece of clothing is 50 yuan, but now it is sold at a 10% discount. How much is the price of each piece cheaper than before?
一种衣服原价每件50元，现在打九折出售，现在每件的售价比原来便宜多少元？
<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">50 * (1/10)</gadget>
<output>5</output>

<result>5</result>