This paper has been replaced by 0860.
Let A be a regular F_p-algebra. The K-groups of A[x]/(x^m) relative to the ideal (x) were evaluated earlier by the author and Ib Madsen in terms of the big de Rham-Witt groups of the ring A. In this paper, we evaluate the maps of relative K-groups induced by the canonical projection f : A[x]/(x^m) --> A[x]/(x^n). The result depends strongly on the prime p. It generalizes work of Stienstra on the groups in degrees 2 and 3.