One of the concepts we went over fairly recently is regrouping numbers. In Right Start, they call this the "9's trick". For instance, if you have 9+5, you can take one from the 5, give it to the 9, and then you have a much more workable problem: 10+4. Since the whole concept of Right Start is to get the child thinking in terms of 10's and 5's, a problem like 10+4 is much easier to a child raised on RS, than a problem like 9+5 is.
As a child, I would work out my math problems like this--9+5 is...10, 11, 12, 13, 14. 9+5 is 14. Yes, I know, that's nuts, isn't it? I was never taught another way. But the 9's trick, is just that--a better way to think about math.
Right start also teaches the child to do this for problems involving 8 (taking 2 from one number and giving it to the 8, so 8+4 becomes 10+2).
One of the manipulatives that the Right Start program relies on is the AL abacus. It differs from a regular abacus in that it has 5 blue beads on the left and then 5 yellow beads on the right. This allows the student to not only see groups of ten (there are ten beads on each bar), but also smaller groups of 5 as well. Right Start uses the abacus to teach regrouping, or completing the 10 in this way:
You can see how they are doing it again, using larger numbers. They also teach the child how to use the back side of the abacus to work these problems. I look at the back side of the abacus almost like a place value chart. Beads are entered in pairs of twos (unless the number is odd of course). There are two wires for each place (1's, 10's, 100's, and 1000's). Thus the child can work problems well into the thousands using concrete materials. Little Bean really caught on to this concept, so he did not need to use the physical abacus at all for the 9's trick. As he puts it, he "uses the abacus in his brain," and "moves the beads with his eyes". :)
Tell me again why I love Right Start?? Oh, wait, I already know! ;)