1. Introduction to Sigma Notation1.1. Meaning of Σ (Summation)1.2. How to Read a Sigma Expression2. Sum of First n Natural Numbers2.1. Formula for \(\sum_{k=1}^{n} k\)2.2. Example3. Sum of Squares of First n Natural Numbers3.1. Formula for \(\sum_{k=1}^{n} k^2\)3.2. Example4. Sum of Cubes of First n Natural Numbers4.1. Formula for \(\sum_{k=1}^{n} k^3\)4.2. Example5. Patterns in Special Series5.1. Square of the Sum Pattern5.2. Visual Understanding