Khan Academy — free education resources for all ages

Khan Academy offers a wide range of free online lessons, practice exercises and instructional videos in maths, science, computing, history and more, suitable for school-age learners and adults. The content is free worldwide and can be used by parents, teachers and students to support classroom learning or home study; registering for an account is optional but enables progress tracking. Access the full library at the Khan Academy website or via its apps at no cost.