I am thoroughly enjoying this discussion!
There are so many different ways to approach teaching math concepts, and it is great to be able to discuss how different families handle similar situations. All families are going to be different in their approach, and I enjoy seeing the diversity of approaches!
One thing that struck me in this thread was deltagal's comments that she noticed standardized test scores going down in math as her kiddos get older. This is something that is actually not uncommon as kiddos grow and mature. This is because as the years pass, kiddos true areas of expertise and excellence become more readily apparent, and the areas of struggle begin to show themselves more and more (reflecting in children's test scores).
As the years pass, the material in each subject area becomes more and more comprehensive and the application becomes much more difficult. Math and science are two of the skill areas test-wise where you will really see changing test scores begin to happen as kiddos get older. In the younger years it isn't uncommon for many kiddos to do well in most areas on their standardized tests. As kiddos age, and the breadth and depth of content increases, this is no longer true. The gap widens between those who are truly gifted or strong in these areas to those who are not. This is why the ACT/SAT subtest scores are so meaningful to colleges, because a student's skill and academic competence in each subtest category is one indicator of a student's natural abilities.
The middle school years are definitely years where the division begins to take place in those who excel in certain areas and those who have a harder time.
I agree that with review and practice, you can make some difference in a child's scores. I've also seen the flipside of too much review and additional practice causing frustration in some kiddos too, if repeated review and practice is taking place in an area that is already a struggle. Repetition is good, but there must be balance. This is why one answer doesn't fit all situations when it comes to how much review is enough.
The age, maturity, and personality of the student will make a big difference on how much review is acceptable and beneficial. In the younger years, I tend to partner with the kiddos as much as needed to help them be successful. Steady progress forward is the goal. I also want to be sure kiddos don't come to feel that they are not good at math and cannot do it! As kiddos mature, I want them to move toward more independence, and I expect them to move toward more mastery. If the children in the upper levels are not retaining as much as I'd like, I'm much more willing to reteach. The varying levels of math discussed in this thread definitely make a difference in the approaches shared about review.
So, keep this in mind as you each find what fits your family best in this area.
Blessings,
Carrie
Am I wrong? 
I think it is just one more opportunity to give little tips of how to mentally think through solving a problem. Singapore math is rigorous. The reviews are hard. I think it is fine to offer a little help, especially to a teary-eyed little one. 
1A (writing number words) and 3A (long division). I had to come along side both of them at times, but once their memories were refreshed they were able to do their work. With having just read this thread, I did not fret to have to come along side them. It is so important to keep in mind that we are teaching our children, not the subject 