Evidence for polynesian contact with the Americas is mounting. Regardless, the medieval coonization of all the pacific islands is evidence of seamanship and navigation skills European mariners didn't achieve until well into the age of sail. European sailing was much more trade/cargo oriented & we know a lot less about "pre-contact" polynesian maritime cultre so it's hard to do put the technologies side-by-side. That said, it looks the polynesian ability to aim for and land on small remote islands circa 300CE was not surpassed by any other culture until the 18th century.
Then there's the strange case of Easter Island with it's giant stone statues. Giant stone statues & "how-the-f%£$-did-they-do-this" megalithic monuments have existed for a long time (EG the sphinx), but these are usually produced by populous civic cultures. "High civilization" to use an out of date term. For a tiny island to produce this kind of an artistic culture without obvious predecessors or descendants is strange.
As always in prehistory (in the literal, "before written records" sense), what we know is very little. But, it wouldn't be hard for me to believe that surprising numerical or mathematical systems existed there. It's a culture that has surprised us to the point of disbelief several times.