Scientific American reports on three individuals who retained remarkable mathematical skills after brain damage that left them unable to use language to communicate.
Varley and her colleagues found that although the subjects could no longer grasp grammatical distinctions between, say, “The dog bit the boy” and “The boy bit the dog,” they could interpret mathematical formulas incorporating equivalent structures, such as “59 – 13” and “13 – 59.”
Although subjects easily answered simple problems expressed in mathematical symbols, words continued to stump them. Even the written sentence “seven minus two” was beyond their comprehension. The results show quite clearly that no matter how helpful language may be to mathematicians–perhaps as a mnemonic device–it is not necessary to calculation, and it is processed in different parts of the brain.
This suggests that maths ability does not necessarily rely on written or spoken language to give calculations logical order and coherence.
Link to Scientific American story ‘Math without Words’.
Mind Hacks 
But because the participants in this study were not brain damaged from birth, this research does not rule out the possibility that the acquisition of mathematical ability might depend on language, either in an individual’s development, or evolutionarily. http://bps-research-digest.blogspot.com/2005/04/words-cant-explain-maths.html
This could just mean that e.g. the bits of the brain that parse a sentence (mathematical or in natural language) are separate from the bits needed for language comprehension or production. And a hundred other things.
Also, mathematics is rather a large field. That someone can spot that addition is commutative or grasp the ordering of real numbers despite “having no language” (whatever exactly that means) is interesting, but could they product an argument for why addition is commutative? Could they show how to construct a multiplication function given addition? Could they prove other properties of arithmetic, speculate other properties? It would be interesting to ask mathematician to help produce more tests — they certainly should have been consulted before the article was published. It would be a bit nicer if instead of using the word “mathematics” people would be more precise and say e.g. arithmetic calculation.