This question might get closed, so you might want to copy any answers you get and save them right away. ;)
One thing to watch out for: it's common to use "game design" and "game development" interchangeably, but design is just one skill in an ensemble. Here's what I can say about being a game designer, but note that there are many more ways to take part in game development, and many more roles to fill.
Why did you choose your career?
I love solving problems - especially ones that demand a mix of creative thinking and more technical figuring.
What kind of education did you have to complete for this career?
I studied industrial design, which is about designing products for mass consumption (like toothbrushes, cars, etc.) My school focused on user-centered design, which involves thinking about how the person using the product (your player) thinks/feels/wants, and using that to guide design decisions.
Other game designers I know have studied architecture, economics, psychology, education, language, etc. Some designers I know got into games straight out of secondary school. So there's no hard requirements.
A few programs are available now specifically tailored to game design and game development, but they're not the only way in.
How is math related in this career?
As a game designer, one of the main jobs is defining and tuning the rules for how the game acts. How fast can the player move, how often does this item show up, etc.
Math is a great way to specify those rules concretely, so the computer can execute them exactly as you intend. It's also helpful for predicting what those rules will do - extrapolating out to the extreme cases that are hard to test directly, like "how long will this boss battle take with 60 players fighting at once?"
Once you have a mathematical model for part of a game, you can play with the numbers to find the right balance, so that the game never becomes too easy or too hard, so players are properly rewarded and can progress at a comfortable pace, and so multiplayer remains fair.
What would a day in your normal life in this career typically look like?
My days are pretty weird, and I like them that way. Unlike other jobs where I might have a standard routine, in game design I'll bounce between playing & researching games to get a baseline, meeting with colleagues across the studio to get their input, making and giving presentations to the team about new feature proposals, drawing mock-ups and programming prototypes, documenting & diagramming approved features, crunching numbers in a spreadsheet to balance the scoring and store prices, playtesting to ensure features are working right and identify bugs, and a dozen other tasks.
How do you dress for this career?
Usually jeans and a T-shirt or dress shirt. Most game studios I've been to have fairly easygoing dress codes.
What is your favorite part about this career?
The variety. There are many jobs where 90% of the problems you deal with each day have been solved long before, and it's just a matter of following the steps. Game development isn't often like that. We're usually trying to do at least one thing we've never done before, maybe something that nobody has done before, so we need to come up with our own new solutions. It's terrifying and exhilarating and often fails, but I love the striving.
What kind of games do you create?
So far my portfolio is mostly 3rd-person action games, but like many designers I'm not tied to any one kind of game. I'd love to work on a 2D puzzler or a sprawling RPG or RTS or anything else that comes my way. :)
You might also like to check out Game School Prep, a blog about studying to enter game development. It's run by a producer at my studio, and it's just getting started, but it's already got some excellent info.