The current price of a commodity is 30 yuan, which is 10 yuan lower than the original price. How much is the reduction.
一件商品现价30元，比原价降低了10元，降低了多少．
<gadget id="calculator">30 + 10</gadget>
<output>40</output>

<gadget id="calculator">10 / 40</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>