The wholesale price of a newspaper is 2.3 yuan, and the retail price is 2.5 yuan. Xiao Ming earned 50 yuan by selling newspapers on Sunday. How many copies of newspapers should he sell at least?
一份报纸的批发价是2.3元，零售份是2.5元，小明用星期天卖报赚了50元钱，他至少要卖多少份报纸．
<gadget id="calculator">2.5 - 2.3</gadget>
<output>0.2</output>

<gadget id="calculator">50 / 0.2</gadget>
<output>250</output>

<result>250</result>