I may be doing Algebra I tutoring for high school students soon. What are some good resources for exercises and intuitive/novel explanations for topics some students find sticky, etc.? One resource I'm sure I'll be using is the Schaum's Outline of Elementary Algebra, 3ed. What I'd also like is recommendations of videos and video series like 3Blue1Brown, but pitched at the level of 9th grade Algebra 1. That is, I'm looking for videos that are not straight lessons, but explain the intuition or rationale behind a single topic in a way that isn't often taught the first time one encounters that topic.