If your child is not interested in his Little Math lessons – or indeed, shows a negative reaction to Little Math – stop using the system for the time being.
Your child's reaction means that this time in his life is not the appropriate one for beginning math lessons. This may be because your child is not developmentally ready to start learning to math.
Alternatively, your child may be attaining another important developmental milestone (learning to crawl, learning to walk, teething), or it may be that he is adjusting to a change in routine (you have moved house, your child has changed schools).
Whatever it is that is making your child unreceptive, put Little Math aside for now, and give it another try in a month or two. Keep doing this until your child does show an interest. We have yet to meet a child who didn't end up loving Little Math!