 I'm Zor. Welcome to Unizor education, math for teenagers. Math is my favorite subject. It was my major in school and it played extremely important role in my career. Did I really need math in my day-to-day life? Do doctors need math? Why do people learn math in school? Most of the people who work at whatever jobs they have, they do not really utilize mathematics as such. Maybe some arithmetic like add a couple of numbers to balance your checkbook or whatever. This is not math. This is just some small stuff. So what's the purpose of studying math in school? Well, let me explain for somebody who doesn't know. What's the purpose of going to a gym and pulling some weights or running on some standing still and running at the same time? It's just physical exercise which exercise your muscles and it helps you to keep basically a healthy way of life. Mathematics for the brain is exactly the same thing as exercise for your muscles. This is for body. This is for mind. And if you want your mind to be healthy, if you want to have a good balance in your life, if you want to be creative at your work, if you want to be able to grasp something which somebody is saying very fast and be able to answer questions very quickly, that's where your mind is actually at play. And that's exactly why you need to develop your mind. There is no other subject. There is no other way to develop your mind rather than studying math. And in studying math, the most important part is not learning about rules, theorems, some properties of certain mathematical subjects. No, this is not important. What's important is to solve problems. And considering math is developed in such a vast subject, there are many different problems of many different kinds. It's like if you go to a gym and you see all the different machines, equipment, this is to develop this muscle, this is to develop that muscle, this is to develop your strengths, this is your cardio, etc., etc. So that's exactly what mathematics is all about. It's the conglomerate of different pieces and if you start studying this particular part of the mathematics, you will develop these particular properties of your thinking, of your brain, of your analogies. And if you do that, you develop some other part of your brain, of your thinking, of your abilities. So solving problems in all the different topics, subdivisions which mathematics presents is the most important part of studying mathematics. Unless you solve problems, you will not really achieve the goal of the whole study. Yes, you will pass your exams, you will get your SAT scores or whatever. And it's definitely helping. However, again, your development, your mind development is dependent on how many problems you solve. That's why on this side we present lots of different problems. Some of them will be presented with suggested solutions, not necessarily the only solutions, by the way. Some of them will be presented for self-study, but it is extremely important to go into all these problems and try to solve it yourself. That's the main purpose of the whole thing. Well, thank you and good luck.