Paolo's Mom Answers Questions About the Universe

I get this question at least three times a week. I went for the straight answer that I could logically think of which was zero. But then backtracked, since I wasn’t sure. My uncertainty now, has resulted in the recurrence of this question, week after week.

I got a reply from one my friends from twitter (@gotcaffeine) who said that it’s sometimes zero, but mostly not.

Reliable old Google let me know that you can’t determine it since infinity isn’t really a number. If you define infinity, you probably can know the answer: like an infinite number of even numbers minus all the numbers equals…something. So yeah, it might be zero - it might not be zero - but generally speaking, infinity isn’t a number so you can’t use operands like minus and plus for it.

Now, I just need to find a way to explain this to my little 7 year old without him killing me with his follow up questions….