Symmetries are presented for
sums of the Legendre symbol (a∕p) over certain subintervals of (0,p). The results
follow from an elementary theorem which establishes linear relations among these
sums. The list of subintervals of (0,p) for which the number of quadratic residues
equals the number of non-residues is extended. Some simple applications to the
determination of the class number of the imaginary. quadratic fields Q() are also
given.