These reformed Math programs are a tremendous mess being foisted on us by "Education" professionals and academics. Instead of teaching one, well-tested method of performing operations (addition, subtraction, etd.), these programs present a number of alternative "algorithms". In Everyday Math (the program my own kids were taught), the standard methods for multiplication and division were not taught and years of drill using alternative (and inferior) methods were used. This leads to tentative confusion over the way to solve problems. Proficiency with basic multiplication and so forth is downplayed and instead proficiency with calculators is developed.
The Education majors (teachers and professors of Education) aren't STEM people themselves. I remember how we, the parents, were lectured (during the parent introduction to these programs) on mathematics and how, we were informed, "there is more than one way to get to an answer" as if this was some astonishing revealed truth. How there was (are you ready for this?) more than one way to do multiplication. Then the teachers would illustrate some method (for example, the Lattice method of paper and pencil multiplication) and with wide and astonished eyes exclaim, "see it gives the SAME result". Now, for those that don't know the Lattice method, its just a method of doing multi-digit multiplication that keeps the intermediate products, which will eventually be summed, in a grid.
Many years ago I was taught the standard methods for computing the basic operations because after centuries of use they have become the prefered methods by people that have to work with numbers. That's why adults haven't bothered to learn the Russian Peasant method or the Egyptian method or whatever. So while our kids will struggle with some new text book, fat and full of colorful pictures that will have pictures of ancient pyramids, the kids in Singapore will by using thin, little black and white books full of exercises, written in English. And then, the kids in Singapore will go on to absolutely kick our asses in mathematics. I've used these Singapore math books, somewhere around the summer after third grade, to reteach my own daughter mathematics. A couple of days ago, she just took the Calculus AP exam after her Junior year in high school, no thanks to Everyday Math.
Not everything about Everyday Math nor Common Core is bad, but some of it is really bad.
It's argued by the people putting these programs in place that they know better and that their programs are supported by research. Have you looked at this supposed research? It's not good. Few well controlled studies done by people in Education departments[1].
The first (so called) research paper listed on the Everyday Math program web site uses Knuth Vol. 3 as justification for studying so many algorithms. It completely misses the point of Vol. 3. It's a book about sorting and searching algorithms. Almost every one of them has some reason for it's use: easy code, fast average performance, fast worst case, works well with a limited number of tape drives (wow!), and so on. This has nothing to do with the desirability of teaching inferior methods of basic calculation to our kids. This paper, which is used to justify some of the core principles of the Everyday Math program is an example of the poor foundation for these reforms to math education in the US.
[1] How Brainy Is Your Major: http://www.psychologytoday.com/blog/finding-the-next-einstei...
[2] Algorithms in Everyday Math http://everydaymath.uchicago.edu/about/research-results/algo...