I have a quite big development experience and I wonder is it possible to start learning math from scratch. I forgot almost everything I know, even school program. Please give me some guidance on this. Where to start what to do. Are there any math books for developers. May be with exercises to write code or experiment, etc...
Any help is appreciated.
Yes, there are math books for developers:
It's hard to say if either one would be a good starting point without knowing what level you're at.
Assuming you have had high school math, I strongly recommend:
Concrete Mathematics, Second Edition
by Ronald L. Graham, Donald E. Knuth, and Oren Patashnik (Reading, Massachusetts: Addison-Wesley, 1994), xiii+657pp. ISBN 0-201-55802-5
I'd review what you should know first (at least a little) before going on to new material. You'll need a good foundation in algebra, and at least some exposure to calculus before trying Concrete Mathematics or even The Art of Computer Programming.
If you want to go from the practical side of computing Robert Sedegwick, has written some books that have source code explaining computer algorithms and theory.