One frequent criticism of the program is that there is little repetition or revision of skills. Some children may need or parents may require more drill work than Singapore Math requires. In fact, in Singapore the children are drilled extensively in addition to this program. I, personally, find drill work to be unnecessary and a bore and my kids agree. But every child and family is different. Singapore Math offers additional extensions to its program for those who need this sort of supplementation. Hand in hand with this complaint, I have heard that parents with mathematically strong children often cruise through this program at break-neck pace. Again, for these parents, Singapore Math offers several supplements to draw out the program and they offer programs for older children as well so your child can (and should) be able to pace herself - whether that means break-neck or slow with lots of repetition. If your child is a kinesthetic learner, Singapore math might not be for you. I still think its methods of mathematical teaching are well worth it for all children but you might find the need for a hands-on supplement. Some people prefer Saxon math in the earlier grades and switch over to Primary Mathematics when Saxon becomes more rote and less kinesthetic. Another option for supplementing is the Math Bag from Common Sense Press which isn't enough to qualify as a math curriculum but is a nice kinesthetic addition to learning mathematical problem solving.
If you are looking into Singapore Math: Primary Mathematics for the older child, please note that the books do not come with answer keys - these are available and must be purchased separately. A prior complaint about Singapore Math was its lack of teacher resources but this has been solved through the creation of Home Instructor's Guides through 4B. I have not seen or used these so I can not attest to the necessity or benefit of them although others have said great things about them. Another prior complaint is that Singapore Math, being international, does not use US methods of measure or currency. There are now US versions of Singapore Math that are available which remedy this complaint.
Bottom Line: If you are afraid to teach your child math and did not do well yourself, this program will teach you, too! It introduces math in a way that isn't traditional in the US and results in children who really think and understand math without any of the drill work or repetition that turns so many of us off to math. Those who start with Singapore Math in the early years seem to have better luck with it and some require hands-on supplements or drill-work supplements but I consider Singapore Math: Primary Mathematics to be an innovative and successful complete math curriculum
