The original price of a commodity is 500 yuan, and now it is going to be sold at a reduced price of 100 yuan. How much is the reduction?
一种商品原价500元，现在准备降价100元出售，降低了百分之几？
<gadget id="calculator">100 / 500</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>