The math textbooks and workbooks used in Singapore have produced the best results in the world. Titled “Primary Mathematics”—but often referred to as “Singapore Math”—the book series is based on the national math curriculum of Singapore.
The focus of Singapore Math is on depth, rather than breadth; a few important concepts are covered in great depth so that students can master them. In contrast, the focus of the math curriculum in the U.S. is on breadth.
Because of the success of Singapore Math, many schools and homeschool parents in the U.S. have adopted the method.