Brain Game: Counting Letters

Here's a new mentalfloss.com Brain Game Free-for-all Friday challenge. Enjoy!

What's the next letter in the following series, and why? O, E, O, E, R, E, X, ?

Here is the ANSWER.

THE ANSWER:

N.

The letters represent the last letter in each digit, starting with 0:  zerO, onE, twO, threE, fouR, fivE, siX, so the next is seveN.

Thanks for playing, and have a great weekend!