Massachusetts Institute of Technology: Srini Devadas and Eric Lehman's "Sums and Approximations"

Study Section 3.4 "Approximating 1 + x."

Product computation is similar to the evaluation of the product of numbers in arithmetic. Product or multiplication is a binary operation that is commutative [i.e. a times b = a b = b a]; associative [i.e. (a b) c = a (b c)]; and has an identity (i.e. a times 1 = 1). In addition, there are some tricks that can be used.

Some simple properties of products are:

1. a ∏ pi = ∏ a pi, where the ∏ ranges over a set of positive integers i.

2. ∏ pi ∏ qij = ∏ pi qj, where the product symbols varies over ranges for i and j.

Click https://s3.amazonaws.com/saylordotorg-resources/wwwresources/site/wp-content/uploads/2011/09/CS202-Summations.pdf link to open resource.