## Operation Counting $\begin{array}{l}{{\displaystyle{\sum_{i=k}^{m}\,1\,=\,m\,-\,k\,+\,1}}}\\ {{\displaystyle{\sum_{i=1}^{m}i\,=\frac{m(m\,+\,1)}{2}=\frac{m^{2}}{2}\,+\,O(m)}}}\\ {{\displaystyle{\sum_{i=1}^{m}i^{2}\,=\frac{m(m\,+\,1)\,(2m\,+\,1)}{6}=\frac{m^{3}}{3}\,+\,O(m^{2})}}}\end{array}$