There are some great summaries linked below. You will likely want to be sure that any summary you put together focuses on the moral of the story, the way that Miss Moore decides she is going to help Sylvia and her friends understand the disparity that exists just in their city between the haves and the have-nots.
The story is relatively straight forward: Miss Moore decides that a trip to FAO Schwartz, the famous toy store in Manhattan, would be a good way for them to see the difference between opportunities and lifestyles from the slum in which the children live.
They take a taxi to the store and very quickly start to marvel at the fact that people out there could actually spend more than $1000 on a toy boat. The disparity quickly becomes apparent and the children are hilariously honest about what they see.
At the end of the day, Sylvia and Sugar discuss what they learned with Miss Moore, and Sylvia, upset by what she's seen, plans to go off alone to contemplate the meaning of it all.