The current price of a watch is 180 yuan, which is 20 yuan cheaper than the original price. How much is the current price lower than the original price?
一块手表现价180元，比原价便宜20元，现价比原价降低了多少．
<gadget id="calculator">180 + 20</gadget>
<output>200</output>

<gadget id="calculator">20 / 200</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>