Well, tbh I am pretty ignorant about math but I will give it a shot.
Unlike science, which is driven by empirically falsifiable hypotheses, math is driven by deductions and calculations from set definitions. Math is assumed to be a universal set of understood rules/processes and that would not vary based on language/culture (ie, you may have different words for 1 but the calculation of 1+1=2 is the same in any thinking system and will always be valid). In fact I believe many of the attempts to communicate with potential alien intelligences are math because there is the assumption that our math would be the same as their math, even if our language, culture, and thinking were radically different on everything else.
This article challenges those assumptions. To the extent the tribe has no concept of numbers in our sense (no concept of 1, much less 1+1) yet can still accurately calculate and solve mathematical problems, they are using some system of math that is different than our own. If this holds, this means our math is not the one true universal way.
Or so it appears to a guy who took like one math class in college, has no background training or expertise whatsoever, and just wanted to look cool on the intarblawg. =/
