Zach Korzyk was a math teacher at Manhattan Village Academy for 13 years. He created DeltaMath ten years ago for his own needs as a teacher but opened it up to other teachers to use for free. Since then the website has been used by over 100,000 teachers and more than 3 million students. He recently went full time with DeltaMath to concentrate adding new content and features to better address the needs of teachers and students.