Multi-way parallel mathematical operations along arbitrary transmission paths are constructed based on realizable planar discrete metamaterials in this paper. The introduced method of “computational metamaterials” is used to perform the desired mathematical operations. For producing high-efficiency devices, the function of multi-way parallel mathematical operations is indispensable in advanced analog computers. Therefore, in this paper, we propose the arbitrary transmission paths that can be implemented by the bending of the electromagnetic waves based on the finite embedded coordinate transformations, which has a strong potential to realize the function of multi-way parallel computation. Nevertheless, owing to the inherent inhomogeneous property, metamaterials are difficult to be achieved in nature currently. In order to make it possible for fabricating in practical applications, the planar discrete metamaterial is a promising medium due to its homogeneous property. Numerical simulations validate the novel and effective design method for parallel optical computation.