New Zealand has the following coins:
As you can see the smallest coin is the 10c piece - therefore when shopping, prices are rounded up or down in the following way (known as the Swedish rounding system):
if the amount ends in 1,2,3,4 - the amount is rounded down to the nearest 10 - so $12.34 becomes $12.30 if you are paying for something
if the amount ends in 6,7,8,9 - the amount is rounded up to the nearest 10c, so $12.98 becomes $13.00.
if the amount ends in 5, it is up to the discretion of the shop owner how rounding occurs but generally it is rounded down, so $12.35 becomes $12.30.
This can be confusing until you get used to it but it does mean that you don't need to be carrying a lot of small value coins.