2 Classic Montessori Math Curriculum in One Set: Decimal Square Board for decimal & square number learning and Gradient Concentric Geometry Tray for size/shape discrimination, covers pre-algebra calculation and planar geometry cognition in one package Gradient Concentric Shape Tray (Triangle/Circle/Square): 3 basic geometric shapes with layered concentric nested design, available in red/yellow/blue three bright solid colors. Kids observe gradual size change of nested figures to learn shape matching, size comparison, visual grading & plane contour recognition Color-Coded Decimal Square Calculation Board: Graduated colorful plastic bars & small unit blocks follow montessori decimal system rule, different color corresponds to tens/units/hundreds digit value. Visually demonstrate square number, addition and decimal composition, turn abstract arithmetic into tangible block operation Premium Natural Beech Wooden Storage Tray: All trays crafted from solid beech hardwood, smooth polished burr-free edges; geometry pieces made of eco soft rubber, decimal blocks with non-toxic pigment. for preschoolers daily grasping and sorting play Visual Discrimination & Spatial Sense: Gradient shapes train visual grading, size sequencing and shape classification; Decimal square set builds early decimal & square number concept, lay pre-algebra foundation