for the most part, they didn't go for bigger than 27 very often. At the time Saxe started studying them in the late 1970s, they were living very close to nature

for the most part, they didn't go for bigger than 27 very often. At the time Saxe started studying them in the late 1970s, they were living very close to nature, and often didn't have cause to need to accurately count higher than that (if you have one or two fish, the distinction is important - if you have 27 or 28, less so). But yes, the word fu (not foo, but enjoyably similar) which kind of means "a full amount", or enough, and was used as "one radix", so people do something like fu + another number word to mean 27 + that other number. I don't remember if there was evidence of treating it like a radix (like multiple fu + something), but I don't think that happened. Again, in this particular culture and economy, there wasn't much of a need to think about large numbers precisely. Which is part of what makes all this pretty fascinating - humans have some inbuilt capacity to reason about numbers (some studies of babies show that they can distinguish between two and three of things just as readily as two hundred to three hundred, sort of a visual field scale independence - I'd have to dig to find that study, I read it about eight years ago, I think it was in nature), but beyond a certain level it becomes intrinsically intertwined with our development of language and other conceptual frames.