Mathematics

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

Pythagorean Theorem in Math — Learn about the Pythagorean theorem in geometry. Get its definition, formula, and worked example math problems.

Pythagorean Theorem – Definition, Formula, Problems

This entry was posted on December 26, 2021 by Anne Helmenstine (updated on November 11, 2025)

The Number Zero Definition and Facts — Learn about the number zero. Get the definition and interesting zero facts and learn about its history and role in math.

Number Zero Definition and Facts

This entry was posted on December 19, 2021 by Anne Helmenstine (updated on May 28, 2025)

How to Calculate a Tip — Learn how to calculate a tip without a calculator easily in your head. See examples and know how much to tip for different services.

How to Calculate a Tip Without a Calculator

This entry was posted on December 9, 2021 by Anne Helmenstine (updated on December 12, 2021)

What Is an Exact Number - Definition and Examples — Learn what an exact number is in chemistry, physics, and math. Get the definition and examples of exact numbers.

What Is an Exact Number? Definition and Examples

This entry was posted on September 19, 2021 by Anne Helmenstine (updated on December 19, 2021)

Degrees to Radians Angle Conversion — Learn how to convert degrees to radians and back again. This is a key angle conversion in geometry and trig.

How to Convert Degrees to Radians – Angle Conversion

This entry was posted on August 28, 2021 by Anne Helmenstine (updated on August 30, 2021)

Absolute Value or Modulus — Learn what the absolute value or modulus of a number is in math. Get examples and see how to solve absolute value equations.

What Is Absolute Value? Definition and Examples

This entry was posted on July 10, 2021 by Anne Helmenstine (updated on September 27, 2023)

Prime Numbers to 100 — Learn what a prime number is and see how to tell if a number is prime. Get a list of primes under 100 and 1000.

What Is a Prime Number? How to Tell If a ...

This entry was posted on June 30, 2021 by Anne Helmenstine (updated on May 5, 2023)

Real Numbers — Learn what a real number is in math. Get examples of numbers that are real versus those that are imaginary.

What Is a Real Number? Definition and Examples

This entry was posted on June 24, 2021 by Anne Helmenstine (updated on May 28, 2025)

What Is Infinity? — Learn what infinity is in math. Get interesting infinity facts and examples. Learn the properties of this "number".

What Is Infinity? Infinity Facts and Examples

This entry was posted on June 16, 2021 by Anne Helmenstine (updated on November 12, 2025)