Do all the children understand what Ms. Moore is trying to teach?
I have always remained unsure about how much Sylvia learns because she refuses to admit to anything to Miss Moore. She is angry, to be sure, and Miss Moore observes this of her, and she says "I"m mad, but I won't give her that satisfaction." And she later says about Miss Moore, who is teaching the kids about money and disparity, "But she ain't so smart cause I still got her four dollars from the taxi and she sure ain't gettin it." This does not seem to be a very productive lesson that she is learning from the situation. She says at the end when she is racing down the street with her friend to spend the little money they have at Hascombs that "ain't nobody gonna beat me at nothin," which has some ambiguity concerning what she is going to do with what she has learned: will this turn her into a productive citizen so that she makes more of her life (the point of the lesson, Miss Moore must hope) or will she act out resentment and anger in less productive ways such as by trying to trick people (as she does in being less than honest about Miss Moore's money). The girl has an attitude that is very much a product of the economic inequality, and that she will have to deal with if she wants to overcome that.
Surprisingly, Sugar truly understands the lesson. Sylvia is disgusted by the astronomical prices of the toy store, and realizes all the realistic things that kind of money would provide. She thinks of beds, rent money, and a trip to see her grandfather. However, Sylvia sees the recognition that can be attained by a show of wealth. She is angry at her inability to have extravagant things. She feels a helplessness at her poverty. Sugar questions democracy when there is such an inequality in citizen's ability to money and material goods. In this way she grasps the lesson that poverty can be overcome by promoting a change. Mercedes merely comes away with the wish to be more like the white's who spend lavishly on toys.
It's hard to say that all the children understand, but certainly some grasp the lessons about dispartiy. For example, "Sugar questions whether a nation in which some people have so much but others have so little is truly a democracy. Sylvia grows angry at the disparity that she sees, and she also recognizes the potential showiness of wealth, as represented by the woman who wears a fur coat despite the hot weather. Mercedes, in contrast, aspires more to be like the white people who spend so much money on toys." Ms. Moore helps the children to understand what they are already aware of...the unfairness of life.