The topic of this undergraduate thesis is didactic materials for developing early mathematical skills in preschool children. Mathematics is a science that teaches children to perceive and understand relationships in the environment around them and helps them develop thinking and other mental skills. It exists in every aspect of our daily life. Strong foundations for it's adoption should be established in early childhood and preschool settings. Children explore and understand the world through play, investigation, and everyday activities like handling and interacting with objects. Children explore and understand the world through play, investigation and everyday activities like handling and playing with objects. Children engage with their environment using their senses, which serve as natural tools for learning and discovery. Engaging directly with objects in a child’s surroundings fosters the growth of fundamental mathematical comprehension. The National Curriculum for Early Childhood and Preschool Education (2014) considers mathematical skills to be important for lifelong learning. Following this idea, in preschool institutions it is necessary to offer activities with which children will acquire basic pre-mathematical skills from the first time they enter. These skills include understanding spatial relationships, comparing, sorting, and matching, recognizing numbers, counting mechanically, and combining numbers with quantities. In the introductory part of the paper, I will present the theoretical foundations that explain the process of learning mathematics in children and why it is important, followed by stimuli created from pedagogically unstructured material that can help children acquire the concepts of numbers, geometric shapes, basic addition and subtraction, and research on mass and volume and time.