Condition number
As a rule of thumb, if the condition number κ ( A ) = 10 k {\displaystyle \kappa (A)=10^{k}} , then you may lose up to k {\displaystyle k} digits of accuracy on top of what would be lost to the numerical method due to loss of precision from arithmetic methods. However, the condition number does not give the exact value of the maximum inaccuracy that may occur in the algorithm. It generally just bounds it with an estimate (whose computed value depends on the choice of the norm to measure the inaccuracy).
Condition number-4