# Mathematics Learn about the different types of triangles. See examples and understand how triangles are classified by length of sides and angles.

## Types of Triangles Get the definition of a tesseract or hypercube. Learn how to visualize a four-dimensional object and get tesseract facts.

## How to Calculate Percent Learn what scientific notation is and how to use it to write and perform calculations with very large and very small numbers.

## Scientific Notation – Working With Exponents The number π or pi is a mathematical constant that is the ratio of a circle’s circumference to its diameter (π = C/d). The ratio is a constant no matter what size of circle is used. Pi is also called Archimedes’ constant. Although pi is often approximated as 3.14159, its […]

## Pi Facts – What Is the Number Pi? Positive and negative numbers are two broad classes of numbers that are used in math and also everyday transactions, like managing money or measuring weight. A positive number has a value greater than zero. Its sign is positive, but it is usually written without a plus sign in front of […]

## Rules for Positive and Negative Numbers Look up unfamiliar definitions in this math dictionary for kids. It covers arithmetic, algebra, geometry, statistics, and trigonometry.

## Math Dictionary for Kids Have ever wondered how many zeros are in a million, billion, or trillion? Do you know how many zeros are in a vigintillion or a googol? Knowing how to write ordinary large numbers is useful for science or math class (or your bank account, if you are rich). Use your knowledge […]

## How Many Zeros in a Million, Billion, and Trillion? Law of Cosines example problems showing how to derive the law and how to use it to find the lengths of the sides or angles of a triangle.