2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/61877We classify gradings on matrix algebras by a finite abelian group. A grading is called good if all elementary matrices are homogeneous. For cyclic groups, all gradings on a matrix algebra over an algebraically closed field are good. We can count the number of good gradings by a cyclic group. Using descent theory, we classify non-good gradings on a matrix algebra that become good after a base extension.13 pagesRings and Algebras16W50text