Money Exchange

So interesting experience at the shops yesterday... Our roommate Camilla gave us a list of new junk food we had to try so we walked to pack and save (the grocery store) after dinner. We picked up some ginger beer and different kinds of biscuits (cookies) and lollies (candy) and headed over to the cash register. Of course no grocery store experience is complete without a little competition at the check out line. I was doing pretty good until it came time to hand the girl my money. The total came to $8.43 so I got out a 20 and a few coins. I only had two 20 cent pieces and one 50 cent piece. So naturally I hand the girl my 50 cent piece. She then gives me the strangest look and says why don't you give me your two 20 cent pieces? Because I owe 43 cents and those only add up to 40 I reply as I try to hand her the 50 cent piece again. She says I know and you only owe 40 cents not 43. Now I'm confused... I look at the register showing the total and tell her that it says there I owe 43 cents. Starting to get impatient she says that they don't have 1 cent pieces and just to give her the 40 cents. Still a little unsure I give her the money and left. I looked at the receipt on the way out and sure enough they round up or down for the total amount. Weird! But hey I saved 3 whole cents! Sara had no idea that they did that either and we talked to Julie about it afterwards. The smallest coin they have is a 10 cent piece. So crazy!! Haha well now I know :)