Or forget about the thumbs and just count fingers. 8 would be a better base than 10 for sure, and arguably better than 12. (Easier doubling and halving, easier

Or forget about the thumbs and just count fingers. 8 would be a better base than 10 for sure, and arguably better than 12. (Easier doubling and halving, easier binary conversions, but fewer integer factors and fewer digits.)