Restklassenringe (Z)/mod 9/Additionstafel

$\begin{array}{cccccccccc}+& 0& 1& 2& 3& 4& 5& 6& 7& 8\\ 0& 0& 1& 2& 3& 4& 5& 6& 7& 8\\ 1& 1& 2& 3& 4& 5& 6& 7& 8& 0\\ 2& 2& 3& 4& 5& 6& 7& 8& 0& 1\\ 3& 3& 4& 5& 6& 7& 8& 0& 1& 2\\ 4& 4& 5& 6& 7& 8& 0& 1& 2& 3\\ 5& 5& 6& 7& 8& 0& 1& 2& 3& 4\\ 6& 6& 7& 8& 0& 1& 2& 3& 4& 5\\ 7& 7& 8& 0& 1& 2& 3& 4& 5& 6\\ 8& 8& 0& 1& 2& 3& 4& 5& 6& 7\end{array}$