Patent US 5,274,580

A computer and method that can be used in digital computers to calculate the inverse I of a number D. The inverse is approximated by I2 after the application of a complementary correction Cjl to an approximation I1 obtained by linear approximation on the basis of a first value Io which in turn is obtained on the basis of an inverse table. The correction value Cjl is obtained from pre-established data CBl and Hj that are memorized in tables of reduced dimensions.