A geometric series is a list of numbers where each number, or term, is found by multiplying the previous term by a common ratio *r*. If we call the first term *a*, then the geometric series can be expressed as follows:

We call this a **finite geometric series** because there is a **limited** number of terms (an infinite geometric series continues on forever.) In this example, there are 10 terms, the common ratio is *r*, and each of the terms of the geometric sequence follows the same pattern. The first term is *a*. The second term is the previous term *a* multiplied by *r*. The third term is the second term multiplied again by *r* to create , and so on until the last term.