In this talk we shall introduce a dyadic model for the Euler equations and for the Navier-Stokes equations in three dimension. For the dyadic Euler equations we prove finite time blow-up and in the context of the dyadic Navier-Stokes equations with hyper-dissipation we prove finite time blow-up in case when the degree of dissipation is sufficiently small. This is joint work with Nets Katz.