Coinage in most countries is based on a decimal system and coinage denominations are usually in amounts that can easily be divided into 100 but a denomination of 3 does not fit into that equation which classifies it as an odd denomination.
One example of an odd denomination coin is the El Salvador 3 centavos. Originally issued in 1889 the 3 centavo coin was a short series and was only issued for four individual years.
The obverse design features the portrait of Francisco Morazan and on the outer periphery are the words “REPUBLICA DEL EL SALVADOR” and the year of issue.
The reverse design features and open wreath with the denomination “3 CENTAVOS” in the center of the wreath. Located just below the wreath for 1889 & 1913 issues is a mint mark "H" (Heaton Mint of Birmingham, England).
Though only issued for four individual years, there were three different type coins.
Type 1 - Composition of copper/nickel – 1889 & 1913
Type 2 - Composition of copper/nickel obverse & reverse design change – 1915
Type 3 - Composition of nickel & brass – 1974
Mintages by Year
1913H - 1,000,000
1915 - 2,700,000
1974 - 10,002,000
General Market Notes
All three coins are affordable in a grade of VF but in grades of XF or better the 1913 & 1915 issues command much higher prices.