A 10% discount on a piece of clothing is 180 yuan. How much is the current price cheaper than the original price?
一件衣服打九折是180元，现价比原价便宜多少元？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">180 / (9/10)</gadget>
<output>200</output>

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

<gadget id="calculator">200 * (1/10)</gadget>
<output>20</output>

<result>20</result>