I think that it is important to note that without good instruction no method is "good". It is really really important for anybody learning anything to understand fundamentally what is going on. This is the problem with most people that have math phobia's (I don't believe there are people that are not good at math). They are taught to memorize their times tables with only a fleeting mention that this really a summation. On this weak foundation people add more concepts, and BOOM they are math phobic. The thing I do like about the "line method" is it is a very visual way to show children what is going on. The chunks, if you will, are literally the place of the digit.