There are 253 battery cars sold at the battery car sales point, and there are 190 left after 3 days of selling. How many cars are sold per day on average?
电瓶车销售点共有253辆电瓶车，卖了3天后还剩190辆，平均每天卖出多少辆？
<gadget id="calculator">253 - 190</gadget>
<output>63</output>

<gadget id="calculator">63 / 3</gadget>
<output>21</output>

<result>21</result>