A kind of fitness equipment is now sold at 1620 yuan with a 10% discount. How much is the current price cheaper than the original price?
一种健身器，现在打九折出售是1620元，则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">1_620 / (9/10)</gadget>
<output>1_800</output>

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

<gadget id="calculator">1_800 * (1/10)</gadget>
<output>180</output>

<result>180</result>