Description Why do children find geometry so difficult in math? Children who struggle with geometry often have a very limited, fixed image of shapes in their minds. Because of this, they may see the same shape flipped or rotated as an entirely different shape. They may also mistakenly believe they've mastered a geometric concept when they've only learned it through a narrow set of examples. How can children solve problems without using physical objects? When children first begin representing three-dimensional objects on paper, it helps to let them handle and compare actual physical objects. However, geometry skills don't develop through hands-on activities alone. As children build shapes themselves and intuitively grasp the concepts and properties involved, they begin to make mental predictions and then justify them logically. Through this process, their geometric thinking gradually develops to the point where they can solve problems mentally, without needing physical objects at all. So how should children study geometry? Before diving into geometry lessons, it's important to spark interest and motivation so children approach the material with a self-directed mindset. Next, each concept should be introduced visually and intuitively, using a variety of examples so that understanding isn't limited to a single fixed shape or position. From there, children apply and practice what they've learned through diverse problems, strengthening their mathematical thinking and solidifying core concepts. Activities like drawing, measuring, and moving shapes help confirm that concepts have been properly understood while also improving spatial awareness. Finally, challenge problems build on everything learned to sharpen critical thinking and problem-solving skills, pushing children's abilities to the next level. Through this 5-step process — Preparation → Concept → Practice → Manipulation → Challenge — This Is Geometry truly strengthens children's geometry skills. Complete mastery of geometry! The 5-step learning system of This Is Geometry (Red Geometry) delivers real results. [Book Composition] A total of 6 levels, with 3 volumes per level. D1: Movement of Plane Shapes D2: Perpendicular and Parallel Lines / Quadrilaterals (1) D3: Quadrilaterals (2) / Polygons [Recommended Grade Level] Elementary 4th graders who need foundational geometry practice.