I agree with the previous person. Don't stress over this. He has plenty of time to learn. There is more harm done by pushing him, he might dislike learning all together. Give him time to just play and learn about the world around him, count well, know about the animals, environment, do counting games, experiments, phonics games (to recognize the sounds that words start with or end with). Reading letters and numbers will come later. Give him some time even if it means to wait a year or two. He will catch up quickly when he is ready and it won't be the cause of stress for you and him.