Montessori quick calculation is the development and innovation based on Montessori mathematics, which is relatively low and young, and "Montessori quick calculation" is aimed at preschool children, and its greatest advantage is that it is well connected with children and consistent with the calculation method of primary school mathematics. Suitable for kindergarten children in large classes and primary school students in grade one or two. Montessori quick calculation is the perfect connection between Montessori mathematics and traditional exam-oriented education. The disadvantage of Montessori mathematics is that it is impossible to calculate without physical objects when performing multi-digit operations. Montessori's quick calculation is the most effective method to solve the disadvantage of Montessori's mathematics. )