Key Curriculum Press
Their most popular curriculum, The Key to book series, like Key to Fractions, are extremely easy to learn from and parents/teachers/moms can easily follow along if they need a refresher on the topics.Miquon Math is their other most popular and well-known curriculum. This series will introduce all four arithmetic operations and fractions during the very first year. Third year students will already be graphing algebraic equations!
Most popular Key Curriculum Press books
Key to Fractions (Books 1-4)
Key to Decimals
Key to Geometry Complete Set (8 books with answers and notes included)
Exploring Geometry with the Geometer's Sketchpad V5