I just asked both kids and DD (age 8) could do 5 backwards easily and DS (turned 7 a couple months ago) could do 4 but struggled w/ 5. So would that really earn a digit span score of 10-11 for DS? I didn't try forwards but I think for DS it's probably around 6-7 digits. I find it so strange how DD doesn't seem to have any problem with this at all but she looks spaced out if you ask her what's 9+4. DS didn't have nearly as many problems memorizing math facts.