I have read quite a few discussions about Singapore Math on this forum. Many have acronyms like MIF, CWP, HIG, etc. I have compiled an outline here. Hope it helps.
The Singapore Math curriculum was conceptualized by the Ministry of Education in Singapore. It became popular worldwide due to its consistent top ranking on Trends in International Math and Science Study (TIMSS). The early adopters are home school students. Currently Singapore Math is used in 100 over US school districts.
The math learning process comprises three steps which are: concrete, pictorial, and abstract. The concrete step refers to students learning through manipulation of objects like pens, erasers or clips. In the next step, pictorial representations like bar models are used to represent the problem.
The syllabus is about 1 year ahead of syllabus in other countries. For example primary 3 may be equivalent to elementary 4 in other countries. The most challenging word problems are those related to pre-algebra.
Textbook titles with US Edition are listed here below. The titles not only have textbooks but they also have workbooks, home instructor guides and teacher’s guides.
Dimension Math by Singapore Math Inc
Math in Focus by Marshall Cavendish, reseller Houghton Mifflin Harcourt
Challenging Word Problems by Marshall Cavendish
Primary Math Marshall Cavendish
In addition to workbooks, students/instructors can tap on worksheet question banks in free test papers -> Sg Math, for challenging word problems. Grades 4 to 6 are extremely challenging.
About
Marshall Cavendish is a Singapore-based textbook publisher whose publication are used in Singapore schools.
Singapore Math Inc is an US publisher that adapted the curriculum to the American education market