  In this work we define an universal arithmetical algorithm, by means of the
standard quantum mechanical formalism, called universal qm-arithmetical
algorithm. By universal qm-arithmetical algorithm any decidable arithmetical
formula (operation) can be decided (realized, calculated. Arithmetic defined by
universal qm-arithmetical algorithm called qm-arithmetic one-to-one corresponds
to decidable part of the usual arithmetic. We prove that in the qm-arithmetic
the undecidable arithmetical formulas (operations) cannot exist (cannot be
consistently defined). Or, we prove that qm-arithmetic has no undecidable
parts. In this way we show that qm-arithmetic, that holds neither Church's
undecidability nor Godel's incompleteness, is decidable and complete. Finally,
we suggest that problems of the foundation of the arithmetic, can be solved by
qm-arithmetic.
