Mom bought a Walkman, the original price was 180 yuan, and now it only costs 10% off, how much is it cheaper than the original price?
妈妈买了一个随身听，原价180元，现在只花了九折的钱，比原价便宜了多少钱？
<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">180 * (1/10)</gadget>
<output>18</output>

<result>18</result>