The document is a presentation on Simpson's 3/8 rule. It introduces numerical integration and Simpson's rule as an improvement over the midpoint and trapezium rules. It explains that Simpson's rule has two variations: Simpson's 1/3 rule and Simpson's 3/8 rule. Simpson's 3/8 rule is based on a cubic interpolation and is also known as Simpson's 2nd rule, using a polynomial of degree 3. It provides an example C program for implementing Simpson's 3/8 rule when the number of strips is a multiple of three.