We propose an approach for extending a tableau-based satisfiability algorithm by an arithmetic component. The result is a hybrid concept satisfiability algorithm for the Description Logic (DL) [Ascr ][Lscr ][Cscr ][Qscr ] which extends [Ascr ][Lscr ][Cscr ] with qualified number restrictions. The hybrid approach ensures a more informed calculus which, on the one hand, adequately handles the interaction between numerical and logical restrictions of descriptions, and on the other hand, when applied is a very promising framework for average case optimizations.