I'm not that sure about computational intelligence being all that impressive. For instance, that parlour trick you mentioned is common enough to come across (I'm not particularly a super genius but I had it figured out by the time I was in college) that I was surprised that so many people found it useful. Like legit intelligent people were talking about how useful it was on Twitter. Which made me realise that some of us were just quicker with math even if our overall intelligence wasn't spectacular.