One way of summing multidimensional series

It is known that in analysis courses, multiple series are considered only at a conceptual level, and their simplest properties are provided. Two widely used methods for summing multiple Fourier series are the spherical and rectangular methods. The present study is devoted to a new method of proving the convergence of multidimensional series by reducing them to a one-dimensional series, allowing applicating known statements for one-dimensional series to multidimensional ones. Examples of justifying the convergence of numerical and functional series are provided as an illustration of this summing method.