The authors describe a new numerical algorithm for the gradient-enhanced formulation. Using the backward Euler rule leads to a gradient-enhanced formulation of the classical closest-point-projection-method. The plastic multiplier is solved via a dual mixed method, which is a convenient feature in the present context. This leads to an unambiguous representation of the constitutive relations in the equilibrium equation. Moreover, the classical local algebraic Kuhn-Tucker conditions are obtained in a straightforward fashion in the limit case of local theory. The developed algorithm is implemented in an educational finite element package. Numerical results for the extension of a plate in plane stress demonstrate the convergence characteristics with mesh refinement, as well as the salient features of the adopted damage-based constitutive model.