Numerical integration methods are used to approximate the area under the graph of a function over an interval . Select a function and a method to visualize how the area is being approximated. Then increase the number of equal-width subintervals to see that more subintervals lead to a better approximation of the area. The effectiveness of various methods can be compared by looking at the numerical approximations and their associated errors. In particular, you can investigate how doubling the number of subintervals impacts the error. To use the magnifying tool, click anywhere in the graph for a closer look.