The manual contains tasks on all topics of the mathematics course for grade 3. It includes non-standard tasks that expand the basic knowledge system of third-graders.The material of the manual will help students consolidate what they have learned, train their memory, develop logical thinking, and the ability to find the right solutions to difficult problems.When performing non-standard tasks, students train in establishing cause-and-effect relationships, designing a solution, demonstrating not an additional amount of knowledge, but the level of their independence. The level of complexity of all tasks is higher than the basic one, which is why they will be a good training for those who want to participate in school math olympiads.The manual will also help the teacher in the lesson to keep students busy who perform all types of tasks faster than others in the class .For convenience, at the end of the book answers and explanations for tasks that may cause difficulties are given.The manual can be used in the classroom at school and for self-study at home.