I have a disjoint union of open sets $U_1,..., U_k$ on a variety $X$. In Fultons "Introduction to toric varieties", he used $X=X_\Sigma$ a toric variety and $U_i=\mathcal{O}(\sigma_i)$ orbits. He then used $$ A_k\left(\bigsqcup_i U_i \right) = \bigoplus_i A_k(U_i) $$ as a fact. Is this true in ge...