A toy car, originally priced at 20 yuan, is on sale at a 10% discount. How much is the current price?
一辆玩具小汽车，原价20元，打九折出售，现价多少元？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">20 * (9/10)</gadget>
<output>18</output>

<result>18</result>