Law of propagation of errors

The law of propagation of errors is like a game of dominoes. In this game, each domino has a number written on it and when you line the dominoes up, the numbers all add together and you get a final number. The law of propagation of errors is just like that game but instead of numbers, it uses measurements from experiments. When you do an experiment, you measure some things, and each of these measurements has a bit of error or uncertainty associated with it. The law of propagation of errors says that when you add together multiple measurements, the uncertainty in the final result is larger than the uncertainties in the individual measurements. So, if you have three measurements, each with a small uncertainty, the final result might have a bigger uncertainty than the individual measurements. That's the law of propagation of errors.