Well, 1023 to be exact. Using a binary system, you can list out every number from 0 to 1023 with 10 digits. I’ve been trying to teach myself how to do this since I realized I could a few months ago.
Pros:
You can get really large numbers with two hands. (And that’s about it.)
Cons:
Because we’re mostly taught to count by tens, breaking out of the mindset to get useful numbers quickly is rather difficult. Also (because of the above) once we pass about 100 we tend to generalize and having the ability to pick out exact numbers is generally not superior. It’s generally useless to be able to count to 1023 on your fingers because no one knows what the hell you’re doing, too.
Verdict:
Fun to be able to do, but largely useless considering practical purposes and time investment to learn. (Won’t stop me from doing so though…)