We give conditions for the Mayer-Vietoris property to hold for the algebraic
K-theory of blow-up squares of toric varieties in any characteristic, using the
theory of monoid schemes. These conditions are used to relate algebraic
K-theory to topological cyclic homology in characteristic p. To achieve our
goals, we develop for monoid schemes many notions from classical algebraic
geometry, such as separated and proper maps.Comment: v2 changes: field of positive characteristic replaced by regular ring
containing such a field at appropriate places. Minor changes in expositio