Textbooks onlyRight now I am using the textbooks only - not the workbooks or teacher's guides. Our son does not need a bunch of problems to work to get a concept down, and the textbooks provide enough problems. The textbook also provides the graphical explanation of the "Singapore" way to do the problem, which I don't already know, so I need that explanation. He does not work the problems in the book itself - I just write them down on a sheet of paper for him. Also there are many places where I can generate or print practice problems online for free if he needs more practice. The only other books I have bought from Singapore are the new Challenging Word Problems books.
As for manipulatives, our son is still not into memorization and is using a manipulative approach to math. I am going to let him use his manipulatives as long as he chooses them, until he really starts to understand on his own about the numbers and doesn't need them anymore. I have a whole variety of types of manipulatives he can use. I have linking cubes, a vertical abacus (called a linkable abacus - hard to find here now), a set of 200 1" wooden cubes (from a place called Casey's Wood Products), sets of colored bears, poker chips, a set of the 1000 cube, 100 squares, 10 rods and individual blocks from Didax, a bead abacus, and a number line. I just let him pick what he wants to use. I like having such a variety for him to choose from. I did not buy any of these from Singapore Math. Some are from Didax, some are from Rainbow Resources, and some are from other places.
He is also doing well now with using the Singapore methods on paper. He is learning that he can just use marks on paper as manipulatives and not need anything else. As he gets more used to that way, he is choosing it more and more.