These platforms offer complete lessons, instructional videos, and adaptive practice for students. 

• Khan Academy: A widely used platform providing 100% free, standards-aligned instructional videos and practice exercises for grades 6–12.

• DeltaMath: Features thousands of high-quality practice problems with step-by-step hints and immediate feedback for middle and high school math.

• Illustrative Mathematics: Offers a free, open-resource (OER) problem-based curriculum for K–12 math with downloadable printable PDFs.

• Dr. Frost Maths: Provides a vast library of free resources, including instructional PowerPoints, auto-marked questions, and assessment tools.