Montessori Math Materials 5 Sets of Colored Bead Stairs 1-9 for Early Preschool Learning Toy THINKING ABILITY: to train children's initial quantity concept through beads, to add, subtract, multiply and divide. LOGICAL COMBINATION: Through mathematics, logical reasoning, scientific analysis and other forms of thinking, help children learn to reason, draw conclusions HAND-EYE COORDINATION: Through the touch of a hand on a digital puzzle, eye coordination will also help balance the balance of the child's body. WORKMANSHIP:we have professional ,fat salary craftsman team, who have been work for premium educational toy more than 8 years. Every one know the detail technological process. SERVICE: we can supply for free small accessory within 3 year after customers purchase products. If appear buyer receives goods and it was damaged (not human factor).