Khan Academy — free online lessons and practice

Khan Academy offers a long‑standing, entirely free library of video lessons, interactive exercises and practice for learners of all ages, covering maths, science, computing, history and more. UK residents can use it without charge — no payment or subscription required — by creating a free account on the site or using the app. It's suitable for primary, secondary and adult learners seeking self‑paced study, revision support or topic catch‑up, and works on desktop and mobile devices.