NCERT Math Class 9

What Will You Learn?

• How all numbers fit into one big family called the “real numbers,” including rational numbers (numbers like 1/2 that can be written as a fraction) and irrational numbers (numbers like √2 that cannot be written as a simple fraction).
• How to play with polynomials (little expressions made from letters and numbers like 2x² + 3x − 5), how to add, subtract, multiply them, and find their factors (breaking them into simpler pieces).
• How to draw and read points on a flat map called the coordinate plane (the “x–y graph”) and use it to understand patterns.
• How to solve pairs of rules written as linear equations in two variables (like 2x + 3y = 12).
• Why geometry is built from clear rules called axioms and postulates (simple, trusted facts), and how lines and angles behave.
• Why triangles are strong, how to prove when two triangles are the “same shape,” and how to use that to solve problems.
• How shapes like parallelograms and triangles share area tricks, and how circles hide many surprises (chords, arcs, angles).
• How to use compass and straightedge constructions to make perfect shapes and angles.
• How to use Heron’s formula (a special rule for the area of any triangle when you know its side lengths).
• How to find surface areas and volumes of 3D shapes like cubes, cylinders, cones, and spheres.
• How to read data, make averages (mean, median, mode), and understand chance (probability) clearly.