"The United States abandoned its own most worthless coin, the half-cent, in 1857, when a half-cent was worth more than a dime is today." [http://www.nytimes.com/roomfordebate/2012/04/04/bringing-dol...]

We need to drop the paper dollar too. The biggest problem is that the new dollar coin is too close in size to the quarter and people get confused (especially elderly) but I think we have to suck it up and say tough. Some countries even have $2 and $5 dollar coins. As things go more and more digital, we need these denominations less and less.

As for the rounding or difference up to a quarter, make that a federal sales tax to fund currency production. If you pay with cash, you incur an additional cost of up to $0.24 per transaction to support the cost of money. If you pay digitally, you pay the exact amount. Just a thought...... :)

From Wikipedia:

Production of the penny ceased in May 2012, and the Royal Canadian Mint ceased the distribution of them as of February 4, 2013. However, like all discontinued currency in the Canadian monetary system, the coin remains legal tender. Once distribution of the coin ceased, though, vendors no longer were expected to return pennies as change for cash purchases, and were encouraged to round purchases to the nearest five cents. Non-cash transactions are still denominated to the cent.