So, my 5-year-old nephew is obsessed with huge numbers, especially named numbers such as googol, duodecillion, and centillion. The other day I spent some time reciting these numbers to him, and trying (and failing) to describe them. What I need are some cool facts about these numbers, such as "there are 1 quadrillion cat hairs in the world", or "there are not enough stars in the universe to fill one googol".

Besides math, his main interests are super-heroes and, apparently, cars.

I'm not a math or physics guy, so hopefully you guys can help me cheat :P

For a very, very long time, I've had a strange but persistent envy of people who have good "logical" thinking skills or who can do math well. I wish that I was the type of person who could play chess to even a passable degree, as I'm convinced a toddler could beat me. But most of all, I wish I could learn something like calculus, which has held a strange allure for me even as a young kid. But I was failing math as early as the fifth grade, and do not remember even an iota of information about geometry or trigonometry. Ultimately, I dropped out of school altogether.

A year or so ago I started in the "pre-K" mathematics category of Khan Academy, because I had such a low opinion of my own abilities. Sure enough, I breezed by it, but even found some parts of the second or third grade curriculum difficult. It's like I was born completely without numerical ability, but I don't want to go so far as to say I have something like dyscalculia, as I at least read analog clocks and musical notation on a daily basis, and have no problem discerning if a number is bigger or smaller than another. I'm also decidedly not aphantastic; quite the opposite. Something I do have is an extreme distrust or even hatred of my own critical thinking abilities. If I mess up simple arithmetic, I'll beat myself up mentally for being "stupid," or an "idiot," and so on for way too long. It's a habit I learned early. Complicating matters is that I'm in my mid-twenties, so my neuroplasticity is probably not great. In fact, one of my deepest fears is that it's too late for me to learn any new subject to a competent degree.

This might be a ridiculous thing to say, but I'm hoping someone can reassure me that it's possible to learn math as an adult, even for a "hopeless" case like me. If you've been in a similar situation and have found particular resources helpful, I'd really like to see them. Khan Academy wasn't really my thing, but if it's more or less the best option for someone like me, I'll try it again.

I'm creating the concept for a story called The Little Differences. It's about an accountant that, one day, out of the blue, notices that a certain calculation is producing a slightly wrong result. Barely noticeable, nothing world-changing,

He runs it on the computer, tries different software, a physical calculator... everything gives a result that's a little off. When he checks on paper himself, he gets the correct result. But, to his surprise, everyone else tells him that he's the one that's off, and that the incorrect result is actually perfectly sound.

I need something that makes sense, mathematically. The weird result must be something that really is wrong, and not just something that programs sometimes get wrong (I don't want it to be explained at all... I mean, the reason why it is occurring must not be something easily reducible to some well-known malfunction). But it must also be minor enough for someone to miss, something that wouldn't really cause much trouble in the real world (is that possible? IDK).

Lastly: it must be something that I'm able to explain (on some level) to a non-math reader.

So, Tildes math wizzes, what you suggest? :D