Xaktly

Xaktly is an independently created online collection of explanations, worked examples, and practice problems that focuses on high school and early college math and science topics such as algebra, calculus, physics, and chemistry. Written in a conversational tone with plenty of diagrams and step-by-step solutions, it’s particularly helpful for teens who are self-studying or need a second explanation beyond their main textbook. Parents appreciate that it’s straightforward, uncluttered, and free to access, making it a useful backup tutor when they’re rusty on their own math and science. While it’s not a full curriculum with assessments and pacing guides, Xaktly offers strong supplemental support at an excellent price point—zero dollars.