and does this change as they get older?
My DS started school knowing a handful of sounds and recognising his name. No more than that. He could count. He understood one more and one less and could do simple sums in his head. Pretty typical I would guess.
In YR he has made what seems like massive strides in reading, writing, drawing, sports, he is more considerate of others, loads of progress on loads of stuff, I am happy with that. Yet they seem to have been taught no extra maths. We had a parents evening on what to expect in year 1 and again there seems to be not much emphasis on maths. He learns more maths by through talking things through at home with us. Is this because reading is the gateway to other subjects and they need to focus on this at this age? Is it just my school? I am bemused as you need good maths to get the best jobs 
I am just sure the kids are capable of a lot more than they are asking them to do and wonder why they don't spend more time on it.