If what they do is "well described by a bunch of math", they're making calculations.
Unless the substrate is essential and irreducible to get the output (whic is not if what they do is "well described by a bunch of math"), then the material or process (neurons or water pipes or billiard balls or 0s and 1s in a cpu) doesn't matter.
>You've got the direction of the arrow backwards. Map, territory, etc.
The whole point is that at the level we're interested in regarding "what is the process that creates thought/consciousness", the territory is not important: the mechanism is, not the material of the mechanism.
You think that ultimately your brain doesn't also make calculations as its fundamental mechanism?
The architecture and substrate might be different, but they are calculations all the same.