It is a combination of Simpson's 1/3 rule and 3/8 rule method in numerically integrating a given function. It asks the user the number of (equally-spaced) segments on which the function would be evaluated. A 2-segment evaluation is a single application of the Simpson's 1/3 rule; 3 segment is a single application of the 3/8 rule; even segments greater than 3 is a multiple application of 1/3 rule; odd segments greater than 3 is a combination of 1/3 and 3/8 rule.