Turns out it was really good at reading people. It would notice the subtle changes in facial expressions as it tapped the correct number of times. When the horse and participant were blocked by a partition, it couldn't math anymore.
I have a cat that uses buttons to talk - it's not bullshit. It asks for food, for clean litterbox, to play. It understands the concept of "now" and "later". It argues with me when I tell it "no". It uses the buttons when I'm not looking at it.
Took a shitton of training, but now it gets excited for new buttons and tries them out and to see what I do in response to it.