Mathematics
Condition Number: Measuring Numerical Stability
Quick fact
A problem with a condition number of 10^k can amplify input errors by a factor of about 10^k, meaning that a 1% input error could become a 50% output error for a condition number of around 50.
Why this is interesting
Have you ever noticed that even a tiny change in a measurement can sometimes cause a wildly different result? Why do some calculations seem to magnify small errors while others don't?