Less than twenty

When you tried to teach your child to add or diminish the number, then realized it was not an easy task. After all, everything seems easy, but how to explain to your child that he knew, and of course remember all that you say? And here is the solution. Come to the game. and try to do everything here, because the game will be simple examples, but the accuracy of the figures will need to bring to justice. And paddle and helpful.