Rewrite 500 School Educational Pages

I have a set of 500 pages, each around 500 words, that teach core concepts to school-age learners. The material is already drafted; what I need now is a full rewrite that keeps the facts intact while upgrading clarity, engagement, and age-appropriate tone... (Budget: $250 - $750 USD, Jobs: Academic Writing, Article Rewriting, Article Writing, Content Writing, Copy Editing, Creative Writing, Editing, Proofreading)