If you want to participate in the AMC 12 competition, you need to master the following mathematical foundation and skills:
-Basic number theory: prime number, factorization prime factor, divisibility rule (including remainder rule), greatest common divisor and least common multiple, cyclic decimal, fraction, etc.
-Basic parts of algebra: equations, inequalities, Vitta theorem, exponential and logarithmic operations, etc.
-Series: arithmetic progression, geometric progression, complex mixed series and logical reasoning.
-Geometry: parallel lines, trigonometric inequalities, similarity and congruent triangles, height bisectors of triangles, properties of median lines and angles, sine theorems and cosine theorems, quadrangles and polygons, circles, spheres, cuboids and regular polyhedrons.