A piece of clothing is 270 yuan after a 10% discount. How much is the current price cheaper than the original price?
一件衣服打九折后是270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">270 / (9/10)</gadget>
<output>300</output>

<gadget id="calculator">300 - 270</gadget>
<output>30</output>

<result>30</result>