ELI5: Explain Like I'm 5

Cauchy principal value

Alright kiddo, so imagine you have a piece of cake and you want to split it with your friend. But there's a problem, your friend wants the middle piece with the frosting on it, and you can't seem to cut it exactly in the middle. One half has more frosting than the other half.

Now let's apply this to Math. Sometimes, when we add or subtract two numbers, the answer isn't clear. It's because we're dealing with things that have an "infinity" symbol or the number 0 in the denominator. And infinity means that the number is very very big and it doesn't have an end.

The Cauchy Principal Value is like the middle piece of cake that your friend wants, but we can't get an exact answer. So instead, we figure out the answer by taking the average of the two possible answers.

Let's say we have the problem of adding 1/infinity + 1/negative infinity. One answer is 0, but the other answer is infinity. We can't choose one answer, so we take the average of the two answers. The average of 0 and infinity is the Cauchy Principal Value.

So, it's like we're splitting the cake where one side has too much frosting and the other side has too little, but we find the middle part where there's just the right amount of frosting for our friend. That middle part is the Cauchy Principal Value!