With numbers becoming your little one's favorite subject, do not get surprised if he counts backwards with much fluency and accuracy. Though his step will be small say, backward counting from 20, but it is appreciation worthy for a kid of his age.
What you need to know
Counting backwards is a step ahead in his learning process as kids find it difficult to re-learn the counting. Help him wherever required, correct him when needed and appreciate him wherever he deserves it. Never make a mistake of ignoring his efforts. Once he will master from 20, pave way for more backward counting training.