Quoth the dingbat:
Hi Jason
After a long day out yesterday, I returned to find an alert from a friend. They directed me to your blog and, it seems, the source of the 'innumerate dingbat' call.
Well, Greg, I'm not actually sure whether I originated the comment. I just liked it very much. It's so... apt.
I see you've had a go at my maths and concluded "Yes, Greg, you're an Innumerate Dingbat. You're just going to have to learn to live with it."
Well, live with it I will, Jason. After all, you seem intent on sticking with the name, and you're free...