How did Sylvia change after the lesson by Miss Moore?

Sylvia has had a socioeconomic awakening after going to Manhattan. She realizes that America is a land occupied by people who inhabit places and live on an economic level about which she has never even dreamed.

It is interesting that Toni Bambara published her story "The Lesson" in 1972. It was after the Civil Rights Act of 1964—and especially during the 1970s—that racial quotas were restored.  There was a growing awareness in America of the socioeconomic disparities and the need to provide opportunities for minorities. At the time of the setting of this story, there were probably many in Harlem who still had little chance of leaving their neighborhoods. Perhaps, then, the educated Miss Moore, who is not from Harlem, has come there in the hope of making the children aware that other parts of New York are much different from their neighborhood.  She may wish to plant seeds of discontent and the desire for a better life in the children.

Miss Moore takes the children to Manhattan (a wealthy section) so that they can gain an insight into how other citizens of the United States live. On the way, she talks to them about economic disparity. Sylvia remarks,

She’s boring us silly about what things cost and what our parents make and how much goes for rent and how money ain’t divided up right in this country.

After they arrive, the children enter a store where the price tags on various items are astronomical in comparison to the things that they purchase in their neighborhood. On a beautiful sailboat, the tag reads,

Handcrafted sailboat of fiberglass at one thousand one hundred ninety-five dollars.

“Unbelievable,” I hear myself say and am really stunned. I read it again for myself just in case the group recitation put me in a trance. Same thing. For some reason this pisses me off. We look at Miss Moore and she looking at us, waiting for I dunnno what.

“Watcha bring us here for, Miss Moore?” Sylvia asks her, angrily. Miss Moore observes that Sylvia sounds angry and asks her why she is upset, but Sylvia refuses to respond. 

It is not long before Sylvia arrives home, following her and her classmates' uncomfortable excursion to the exclusive shops. On the trip back to Harlem, Miss Moore has asked them to consider the fact that people purchase toys that cost as much as it does to provide for a family of six or seven in Harlem. Sylvia's friend Sugar responds,

This is not much of a democracy if you ask me. Equal chance to pursue happiness means an equal crack at the dough, don’t it?

“Anybody else learn anything today?” Miss Moore asks.

Sylvia steps on Sugar's foot to stop her from talking. She refuses to give Miss Moore any answer. However, after she arrives home, Sylvia declines to go with Sugar "to Hascombs" for sodas. Instead, she goes to a favorite spot:

To think this day through. She [Sugar] can run if she want to and even run faster. But ain’t nobody gonna beat me at nuthin.

Like Sugar, Sylvia has become aware of socioeconomic inequalities, but she also wants to understand what has caused such conditions and how to overcome them. She never again wants to feel inferior to anyone.