Math busters

A guide to understanding subtraction and addition, covering the basic facts and operations, as well as topics such as inverse operations, regrouping, mental math, estimation, word problems, time, money, fractions, and mixed numbers.

A guide to understanding ratios and percents that covers equivalent and reducing ratios, rates, distance, time, proportions, ratios in geometry, scale drawings, models, the golden ratio, proportions, the percent equation, sales tax, simple and compound interest, and more.

Presents lessons and step-by-step exercises in geometry, covering such topics as planes, angles, perimeter, area, volume, and circumference.

A guide to understanding division and multiplication, covering the basic facts and operations, as well as topics such as estimation, word problems, decimals, fractions, and mixed numbers.

A guide to understanding decimals and fractions that covers adding, subtracting, multiplying, and dividing fractions; estimating; terminating and repeating; and percents.

A step-by-step guide to understanding pre-algebra and algebra, covering integers, absolute value, addition, subtraction, multiplication, the distributive property, division, variables and expressions, algebraic equations, properties of equality, and many other topics.