DS6 (gr2) is 25th centile for height and due to skipping one year has boys 6 months to 18 months older in his class. He is one of the shortest but no-one cares. He is friends with both the older and younger boys and enjoys going up to gr 3 for some subjects. Last year he thought we may have missed a birthday over the years and told everyone he was a year older than he was. This year he has worked out that being younger is not a bad thing and happily gives his true age (not that he is asked much at school anymore). The kids don't care, its the adults that might!