Mathematics
Geometry: measure, transform, and justify.
Geometry trains students to see structure: parallel lines, congruent triangles, and formulas that come from dissection rather than memorization alone.
Classroom sequence
Start with precise language — point, ray, angle, vertex — then vertical angles and linear pairs. Use tracing paper or coordinate plots to test translations, reflections, and rotations. Area of parallelograms and triangles comes from rearranging a rectangle. Volume of prisms is base area times height, said in a complete sentence with units.
The Pythagorean theorem is introduced as a relationship among areas on the sides of a right triangle, then used to find missing lengths. Coordinate geometry connects algebra to figures: midpoint, distance, and slope of a segment.