**OK, so we know what a sequence is -- it's a list of numbers (or other things) that changes according to some pattern.**

**So, what's a series? Easy!**

**A SERIES is the sum of a sequence.**

**Here's a sequence:**

**Here's the corresponding series:**

**We have a special notation for series.**

**First, let's get the formula for the nth term of the above sequence... I think it's**

**Do you agree? Does it work?**

**Find the first five terms to check.**

**So, how are we going to let people know that we want to add up all the terms of this sequence and make it a series?**

**We'll use this Greek letter:**

**It's an "S" in the Greek alphabet.Think of it as an "S" for "sum!"**