Small-angle scattering (SAS) experiments applied to nano-scaled systems allow the investigation of the constituents' overall shape, size, internal structure and arrangement. A standard scattering experiment requires a relatively simple setup and is often applied to investigate a system of particles. In these cases, the measured scattering intensity represents an average over a large number of particles illuminated by the incoming beam. The calculation and modeling of the scattering intensity can be performed by the use of analytical/semi-analytical expressions or by the use of numerical methods. In this book chapter, an overview of current available simulation/modeling methods for SAS will be shown either for systems composed of oriented or for randomly oriented particles. Examples demonstrating the use of the finite element method are presented as well as a newly developed method for calculating scattering intensity for oriented particles.