The memristor, meminductor, and memcapacitor are three mem-elements that are commonly utilized in computational circuits and analog signal processing circuits nowadays. Mem-element computing employs non-volatility (memory) to process information in the same physical location where the information is ultimately stored. To apply mem-elements in any given application, it is required to study their properties and behavior. To study the properties and behaviors of any given mem-elements emulators, modeling is required. We have presented mathematical models of memristor, memcapacitor, and meminductor emulators in this article. Memristor may be charge-controlled or flux-controlled depending upon internal variables. So, overall four modeling structures are discussed in this paper.