Please translate this. I don't get it and Google translate answers are funny.
您这是五十块，找您三十块零六毛，请数一下儿。

Also, "一下儿" keeps popping out of nowhere in this book I'm using. What does this mean exactly and when do you use it?

Question

Please translate this. I don't get it and Google translate answers are funny.  
您这是五十块，找您三十块零六毛， 请数一下儿。

Also, "一下儿" keeps popping out of nowhere in this book I'm using. What does this mean exactly and when do you use it?

Answer

一下(儿) after the verb means the action is short
请  数  一下儿。 = please count.

Answer

it's commonly used following a verb, means "a little time" or "for one time", but usually means a little time.

Answer

you have gave me 50RMB, and here is 30.6RMB  for you. please take you a little time to count it out clearly.(make sure i am not giving you less than 30.6RMB) 

一下儿means take sb a little time to do sth

for exemple: 我需要休息一下儿。 I need some rest.(I need rest for a few minutes)
                   停一下儿。 Please stop for a while.

Answer

it have other means is confirm some message.

Answer

"ㄦ" has no any meaning, just like Uh,Ya