The first section on integrals is alive! A section on sums has been separated out into the beginning area for ease of understanding. It's easier to read up on sums and then learn how they're used in integrals, rather than to learn about them both at once. The two sections on Riemann sums have the same practice problems to make it easy to compare the results of the two methods. The definite integral is defined in the last section, and its problem set provides some practice with the rarely used method of computing definite integrals directly from the definition.

More sections soon to come!