This document contains a math lesson on summations. It provides formulas for calculating the sums of sequential integers from 1 to n, odd integers from 1 to 2n-1, and even integers from 2 to 2n. Several practice problems are worked through applying these formulas to calculate sums such as S = 1 + 2 + 3 + ... + 57 and S = 2 + 4 + 6 + ... + 222. The solutions are provided after each problem.