They are returning the ASCII decimal representations of the respective letters. I cannot find anything in the documentation for the Symbolic Math Toolbox real function or the core MATLAB documentation for real to explain it.
for example, this code:
real z
whos
char(ans)
whos
returns this result:
ans =
122
Name Size Bytes Class Attributes
ans 1x1 8 double
ans =
'z'
Name Size Bytes Class Attributes
ans 1x1 2 char
Perhaps one of the MathWorks folks can explain what is going on.