For each of the summations below, the corresponding activity will lead you to explore the recursive nature of sums as well as some patterns generated by sums.

- Summation
1. 1 + 2 + 3 + ··· +
*n* - Summation
2. 2 + 4 + 6 + ··· + 2
*n* - Summation
3. 1 + 3 + 5 + ··· + (2
*n*- 1) - Summation
4. 1 + 3 + 7 + ··· + (2
^{n}- 1)