  We propose a unified approach to addition of some physical quantities (among
which resistors and capacitors are the most well-known) that are usually
encountered in introductory physics such that the formulae required to solve
problems are always simply additive. This approach has the advantage of being
consistent with the intuition of students. To demonstrate the effectiveness of
our approach, we propose and solve several problems. We hope that this article
can serve as a resource paper for problems on the subject.
