I am 14 years old and i am really into maths. I can say that i am really good at it(at what we do at school) and i really want to make a step ahead and start exploring a more complicated sector in maths. I have searched many web sites but what i have found is either too complicated to understand yet, or too easy.
Do you have anything to suggest that would suit me -maybe a book or something like that- that starts slowly with more comprehensible things but then has more advanced and complicated stuff, you know what i mean, i want to start slowly. Thanks in advance, I would really appreciate if suggested something that suits me, cause i have searched a lot!
Try Khan Academy's videos.${}{}$