Dunno - any more clues?
There's another forum member with a birthday soon too, but I think it's a little more than 30! He's taken shoes and socks off to count fingers and toes on his wife, self and 3 kids....and still can't get close!
Wait a minute...1,2,3,4,5,6.....38,39,40......51,52,53,54 ....57 Oh, yes I can! With 2 people to spare! I was never any good at maths