The four number systems available are Decimal, Hexadecimal, Binary, Octal.  Switching between them with a number in the calculation window will convert that number to the selected number system.


Dec (Base 10)

Standard number system and includes integer, decimal, & negatives.  All keys are available.


Hex (Base 16)

A base-16 number system represented by the digits 0-9 and A (decimal 10) - F (decimal 15).  Keys that don't pertain (including many Function and Special Function keys) to this number system are disabled.


Bin (Base 2)

A base-2 number system in which values are expressed as combinations of two digits, 0 and 1.  Keys that don't pertain (including many Function and Special Function keys) to this number system are disabled.


Oct (Base 8)

A base-8 number system represented by the digits 0 to 7.  Keys that don't pertain (including many Function and Special Function keys) to this number system are disabled.