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Making Change

Posted by michael on from the buddy-can-you-spare-an-eighteener? dept.

Roland Piquepaille writes "There are mostly four kinds of coins in circulation in the U.S: 1 cent, 5 cents, 10 cents, and 25 cents. But is it the most efficient way to give back change? This Science News article says that a computer scientist has found an answer. "For the current four-denomination system, [Jeffrey Shallit of the University of Waterloo] found that, on average, a change-maker must return 4.70 coins with every transaction. He discovered two sets of four denominations that minimize the transaction cost. The combination of 1 cent, 5 cents, 18 cents, and 25 cents requires only 3.89 coins in change per transaction, as does the combination of 1 cent, 5 cents, 18 cents, and 29 cents." He also found that change could be done more efficiently in Canada with the introduction of an 83-cent coin and in Europe with the addition of a 1.33- or 1.37-Euro coin. Check this column for more details and references." The paper (postscript) is online.

3 of 935 comments (clear)

  1. Re:Instead... by jmv · · Score: 5, Informative

    In France (and probably other countries) most of the prices end in .00 and the taxes are already included (unlike Canada where I live). It's much simpler that way. If only there was a way to convince stores to do that in here...

    --
    Opus: the Swiss army knife of audio codec
  2. Re:Forget it. by omega_cubed · · Score: 5, Informative
    Quoth Terry Pratchett and/or Neil Gaimen (as they coauthored, and I have no idea which came up with this) in Good Omens:
    NOTE FOR YOUNG PEOPLE AND AMERICANS: One shilling = Five Pee. It helps to understand the antique finances of the Witchfinder Army if you know the original British monetary system:

    Two farthings = One Ha'penny. Two ha'pennies = One Penny. Three pennies = A Thrupenny Bit. Two Thrupences = A Sixpence. Two Sixpences = One Shilling, or Bob. Two Bob = A Florin. One Florin and one Sixpence = Half a Crown. Four Half Crowns = Ten Bob Note. Two Ten Bob Notes = One Pound (or 240 pennies). One Pound and One Shilling = One Guinea.

    The British resisted decimalized currency for a long time because they thought it was too complicated.
    --
    Engineers also speak PDE, only in a different dialect.
  3. 5?! -Interesting +Utter Crap by Anonymous Coward · · Score: 5, Informative

    Cecil has the right answer instead of this complete conjecture.