Chandra M. Hayslett:

It’s also different from American math in that fewer topics are taught in an academic year, giving the instructor the opportunity to teach the concept until it is mastered. “There’s a tendency in the United States to teach a topic, then it’s never seen or heard from again,” said Jeffery Thomas, president of SingaporeMath.com Inc., the official distributor of the math books based in Oregon City, Ore.
The American Institute for Research, one of the largest behavioral and social science research organizations in the world, says Singapore Math is better than American math because Singapore’s textbooks provide a more thorough understanding of concepts, while traditional American math books barely go beyond formulas and definitions. Before someone in Singapore can become a teacher, she must demonstrate math skills superior to her American counterparts, according to the AIR, which is based in Washington, D.C. Additionally, Singapore offers an alternative math framework for low-performing students, but at a slower pace and with greater repetition.