Every person in his lifetime has many times experienced the miraculous impact of the fairy-tale on his imagination, mind and feelings. But we seldom reflect upon the content not only in the ethical aspect of fairy-tales but also as a source of different kinds of knowledge, among them the knowledge of mathematics. The use of fairy-tales in lessons opens up one of the new ways of learning. However fairy-tales are not so widely used in mathematics education in primary schools and preschools. The result of a poll of 86 teachers showed that they approve of the use of fairy-tales in the process of learning mathematics. The analysis of the content of fairy-tales makes it possible to come to the conclusion that here are figuratively and conspicuously seen connections found in the foundation of the theory of probability. Fairy-tales also give a striking reflection of the interconnection between the quantity and measure, there are used different kinds of measures--the thumb (Mary Thumb), an inch (Tom Thumb), at the distance of a call, a three--step length, etc.