Coins/Discontinued

In the 1990s, Australia abolished the 1¢ and 2¢ coins. NZ has abolished the 5¢ coin since. Should we follow suit?

http://www.smh.com.au/money/royal-mint-wants-5-coins-scrapped-20110627-1gmdb.html

However: Consider the change amounts that are possible... what is the optimal way to make change?

5

1x 5¢ coin

10

1x 10¢ coin

20

1x 20¢ coin

30

1x 20¢ coin + 1x 10¢ coin

40

2x 20¢ coin

50

1x 50¢ coin

60

1x 50¢ coin + 1x 10¢ coin

70

1x 50¢ coin + 1x 20¢ coin

80

1x 50¢ coin + 1x 20¢ coin + 1x 10¢ coin

90

1x 50¢ coin + 2x 20¢ coin

Totalling that up, we have:

• 5x 50¢ coins
• 8x 20¢ coins
• 4x 10¢ coins

What about the 5¢, 15¢, 25¢, etc... those are the same as above, plus a 5¢ coin

• 10x 5¢ coins

Of course, these numbers aren't real-world, since some amounts of change are vastly more common than others (needing 5¢ change is common, whilst 35¢ is rare), and often you'll not get the above examples of optimum (most commonly I get 3x20¢ instead of a 50¢+10¢, further diminishing the likelihood of a 10¢ in my change)

...

In my experience, I rarely get 10¢ coins in change - for the reason that my change rarely requires them. I will OFTEN end the day with many 5¢ coins, but they're almost always one-per-transaction.

Abolish the 10c coin?

Nemo says yes

Pro:

• It's not needed much
• Abolishing it requires no transaction rounding since it's rare need can be covered by using 2x 5¢ coins.
• Save manufacturing costs by not needing a whole a coin... that's a full 25% of the silver coin product range!

However, I recognise that there are cons... (or at least, superseding pros to the 5c abolition... Cons:

• Increased locking to retaining the 5c coin, since abolishing that would bring our cash transactions from multiples of 5¢ up to multiples of 20¢ in a single jump! That would be both unpopular, and a difficult transition
• Manufacturing costs are likely better saved by abolishing the 5¢ which has less profit per coin.