Yep. I have a good friend who has it. and she can't so a very simple sum like 15 - 12 in her head. Even though she is very smart in other areas, she just can't do numbers, to an extreme degree. It's kind of funny actually, because I used to babysit her when she was a little girl, and then didn't see her for many many years. I've recently been re-acquainted with her, and she's now a teenager. It's funny finding out now that she has dyscalcula, because I remember suspecting she did as a small child. When she was at the age where she should be learning to count, she had a really unusual amount of trouble learning it. She would attempt to count to ten, and she'd put the numbers all in the wrong order and ultimately only list about 7 or 8 of them, and not in order.
