The factorial function (symbol: !) says to multiply all whole numbers from our chosen number down to 1. Examples:

To find a missing number in a Sequence, first we must have a Rule ... A Sequence is a set of things (usually numbers) that are in order.

A set is a collection of things, usually numbers. We can list each element (or member) of a set inside curly brackets like this

The exponent of a number says how many times to use the number in a multiplication. In 82 the 2 says to use 8 twice in a multiplication, so 82 =...

Math explained in easy language, plus puzzles, games, quizzes, worksheets and a forum. For K-12 kids, teachers and parents.

Exponents are also called Powers or Indices. The exponent of a number says how many times to use the number in a multiplication. In this example:

Symbols save time and space when writing. Here are the most common algebraic symbols (also see Symbols in Geometry):

You can read a gentle introduction to Sequences in Common Number Patterns. A Sequence is a list of things (usually numbers) that are in order.

I love Sigma, it is fun to use, and can do many clever things. So means to sum things up ... Sum whatever is after the Sigma:

A function relates an input to an output. It is like a machine that has an input and an output. And the output is related somehow to the input.