Pre-Algebra
Integers, fractions, percents, exponents, and your first equations.
Foundations
The eight moves everything else in math is built on.
- 01Adding & Subtracting IntegersPositive and negative numbers on one number line.+20
- 02Order of OperationsWhy 2 + 3 × 4 is 14, not 20.+20
- 03Adding FractionsSame-size pieces before you can count them.+25
- 04Ratios & ProportionsTwo ratios that describe the same relationship.+25
- 05PercentsPer hundred — a fraction wearing a different hat.+20
- 06Exponents & PowersRepeated multiplication, with shortcut laws.+25
- 07Variables & ExpressionsLetters that stand in for numbers you don't know yet.+25
- 08One-Step EquationsKeep the scale balanced and isolate x.+30