Welcome to a new post on thoughts-on-cpp.com. This time I would like to start a new series, Numerical Methods. But don’t be disappointed if you’re expecting a new post on the n-body-problem, I’m still planning to continue the “My God, It’s Full of Stars” series. With this new series, I would like to talk about numerical methods which are important in my daily business, starting from Trapezoidal and Simpson integration methods of type Newton-Cotes.