Prealgebra is a term commonly used to refer to the level of mathematics a student studies before moving on to algebra and/or geometry. Prealgebra is difficult to define precisely other than "the math taken before algebra" because of the broad number of subjects that various prealgebra curriculums use.
A typical prealgebra curriculum more-or-less consists of:
- Arithmetic with the natural numbers and integers.
- An introduction to fractions and decimals.
- An introduction to the basics of number theory (prime factorization, multiples, least common multiple, greatest common divisor, etc.)
- An introduction to the basics of statistics.
- Exponents, the root operation, and scientific notation.
- Solving linear equations, inequalities, and modeling word problems using variables.
- Ratios, computing simple conversions and rates.
- An introduction to geometry (computing area, perimeter, angles, etc.).
- the Art of Problem Solving: Prealgebra by David Patrick (Details).
The AoPS classes for prealgebra are a good starting point for those who finished up Beast Academy's curriculum or have a working understanding of simple arithmetic. Note that AoPS's classes are quite challenging as each class is considerably more in-depth and problem-solving-oriented compared to the equivalent typical school course in prealgebra which focuses more on rote memorization.