As in Javascript, awk represents all numeric values using double precision floating point. I have always thought that was a strange (but not necessarily bad) choice for a language that is basically all about text processing. I guess it works out pretty well if you need to do 3D graphics math.
There is a bit of cheating going on here though. Awk doesn't support true multidimensional arrays. They are depending on a Gawk extension for that bit of functionality.