The screening approximation of Ferrell and Scalapino (n /s-1 expansion) is tested in the exactly soluble zero-dimensional case. The expansion is carried to fifth order inn –1, where, forn = 2, it appears to start diverging. Forn=1 divergence sets in at the second-order term. Theself-consistent screening approximation of Bray and Rickayzen converges more rapidly but is more difficult to apply in higher dimensionalities. The usefulness of the zero-dimensional case for checking the enumeration of the Feynman graphs which appear in third and higher order is emphasized.