Middle school students write expository essays to demonstrate their knowledge in their core classes. For this essay, they conduct research, formulate an argument related to the topic and support their analysis with evidence. Prompts for these essays range from literary and historical analysis to making comparisons in science or explaining an equation in math.

Language Arts Essay

The expository essay in a language arts classroom often revolves around a literary analysis. For a literary analysis, language arts teachers ask questions related to characterization, conflict, theme or literary elements. For instance, an essay prompt asks whether a character is flat or round. Middle schoolers answer the question in a thesis statement in the introduction, which also includes the specifics of the story. They spend one to three paragraphs supporting their answer with support from the text. In the conclusion they restate their thesis, summarize the evidence and generalize the importance of their topic. This format is fairly consistent across content areas, with some distinctions.

Science Essay

Students usually conduct more research or base their essay on comparisons in the science classroom. For instance, middle schoolers may see the following prompt: "Compare four organelles of a eukaryotic cell to four parts of something organized such as a factory or computer." For this essay, they write a statement of purpose, or sentence declaring their comparison, in the introduction as well as definitions of relevant terms. Since the prompt specifies four organelles, they include four body paragraphs, each drawing comparisons between the organelle and counterpart in the chosen example. The conclusion includes the student's analysis of how similarly the organelles function as related to the comparison.

Social Studies Essay

Social Studies offers many opportunities for expository essays. Teachers testing for enduring understanding may ask the following: "Identify the Compromise of 1850 and analyze how it contributed to the sectional crisis." For this essay, the introduction includes brief background information and the statement of purpose describing the analysis. Middle schoolers then spend a paragraph identifying the Compromise of 1850 in detail and one to two paragraphs explaining its contribution to the sectional crisis. The conclusion summarizes the points and explains the significance of the issue to the wider topic of the Civil War.

Math Essay

Middle schoolers are sometimes asked to write expository essays in math classes. They solve an equation, explaining in a process essay how they reach their solution. An example prompt is, "If 1 percent of your bill for lunch is 18 cents, and you want to leave a 15 percent tip, how much money should you leave? Explain how to reach the answer and why the method works." The purpose of this essay is to clarify the process of solving a math equation. In a math essay like this one, the introduction consists of the student's restatement of the problem in their own words as well as one sentence that states the solution. One body paragraph explains how the student arrived at the answer; another body paragraph explains the rationale for using that method. The conclusion consists of the problem's significance to mathematics or the world in general. For more complicated equations, students may use graphs or diagrams in the explanation of the solution.