Awell-written summary should be used in place of reading an original text or to you review something that you have already read

to help you review something that you have already read

Explanation:

A summary is the shorter and precise version of the original text. It includes all the necessary details which are mentioned in the text. It helps in over-viewing what the entire text is all about. To summarize means to write about the text including the necessary details. It helps review the text and remember it. Also, the main and important points become easy to revive by reading the summary respectively.

onto a large boat, and mark the water level that the boat sinks to. then, take the elephant out and put a bunch of marked weights onto the boat until it reaches the same water level. add up the masses of the weights to get the weight of the elephant.