If the current price is 85% of the original price, how much is the current price saved compared to the original price?
现价是原价的85%，则现价比原价节约了多少．
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1 - (17/20)</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>