A characteristic of this book is to emphasize the algorithmic nature of numerical solution techniques used in reactor physics. Many numerical solution approaches described in the book are accompanied by Matlab scripts and readers are encouraged to write short Matlab scripts of their own in order to solve the End-of-Chapter exercises. A complete chapter is devoted to lattice code physics, representing an important but relatively obscure component of production calculations. Typical numerical solution approaches are proposed to the reader for building small lattice or reactor physics applications. The precise selection of the numerical techniques is based on their legacy characteristics.