Mathematics

Learn about topics and get worked problems in all areas of math, including arithmetic, algebra, geometry, calculus, probability, statistics, and trigonometry.

Parallelogram Definition and Examples — Learn what a parallelogram is in math, its types, properties, formulas, and how to identify and calculate area, height, and perimeter.

Parallelogram – Definition, Properties, Types, and Formulas

This entry was posted on November 11, 2025 by Anne Helmenstine (updated on November 23, 2025)

Golden Ratio Definition and Examples — Learn about the golden ratio, its definition, examples in nature and design, properties, history, and connections to math.

Golden Ratio – Definition, Examples, Properties, and History

This entry was posted on August 9, 2025 by Anne Helmenstine (updated on May 16, 2026)

Algebra Study Sheet — Download a free printable algebra study sheet with formulas, identities, and common mistakes. Ideal for students, teachers, and test prep.

Algebra Study Sheet

This entry was posted on May 28, 2025 by Anne Helmenstine (updated on June 8, 2025)

Sine Function in Math — Learn about the sine function in trigonometry and geometry, Discover its definition, formula, derivation, and uses. Get worked problems.

Sine Function in Math – Definition, Formula, Examples

This entry was posted on February 18, 2025 by Anne Helmenstine (updated on November 25, 2025)

Cosine Function in Math — Learn about the cosine function in math. Get its definition, formula, and examples in trigonometry, geometry, and calculus.

Cosine Function in Math – Definition, Formula, Examples

This entry was posted on February 4, 2025 by Anne Helmenstine (updated on November 25, 2025)

Order of Operations - PEMDAS or BEDMAS — Learn about order of operations (OoO) in math, abbreviated by the acronyms PEMDAS or BEDMAS. Get worked examples and answers to FAQs.

Order of Operations in Math (PEMDAS or BEDMAS)

This entry was posted on December 17, 2024 by Anne Helmenstine (updated on May 28, 2025)

Circle Revolutions Around Another Circle — Learn how to calculate circle revolutions and the distance circles travel. Also discover the coin rotation paradox and its applications.

Circle Revolutions and the Coin Rotation Paradox

This entry was posted on December 5, 2023 by Anne Helmenstine (updated on January 14, 2026)

How to Add Fractions — Learn how to add fractions. Get step-by-step instructions and examples using simple and mixed fractions and one with negative numbers.

How to Add Fractions

This entry was posted on November 26, 2023 by Anne Helmenstine (updated on May 28, 2025)

Identity Property in Math — Learn about the identity property in math for addition, multiplication, subtraction, and division. Get example problems.

Identity Property in Math – Definition and Examples

This entry was posted on October 3, 2023 by Anne Helmenstine (updated on May 28, 2025)