Expository Writing Across the Curriculum

Contributor: Delaine Thomas. Lesson ID: 12340

Perhaps you think expository writing is just an English / Language Arts exercise, but it is more! This type of writing is used whenever someone is "exposed" to explanations and how-tos. Find out how!



English / Language Arts
learning style
personality style
Grade Level
Intermediate (3-5)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

Audio: Image - Button Play
Image - Lession Started Image - Button Start
  • Did you know that writing to explain a math concept is expository writing?

Explaining any subject, including expository writing, can be expository writing!

Expository writing is writing that is used to inform your audience about a topic.

It is also used to explain how something works or how to do something. This type of writing is used in most of the subjects that you study as part of your education.

Writing about the scientific method in science, and writing about the voyage of the Mayflower, are a couple of examples of how this is accomplished. You can also use expository writing in math by explaining a mathematical concept and how to solve a particular type of math problem.

Before you continue, if you need a refresher on a previous Related Lesson, catch it in the right-hand sidebar.

Take out a piece of paper and a pencil. Take notes about the structure of an expository essay as you watch Eric Buffington's video, Expository Essay:

Image - Video

The structure of the expository essay is much like the structure of other pieces of writing.

The parts are as follows:

  1. Introduction You want to have an attention-getter in this section to make the reader want to read your essay. The introduction also includes the thesis statement that tells your reader what he or she will be learning.
  2. Supporting detail #1 gives evidence and supports the thesis.
  3. Supporting detail #2 gives evidence and supports the thesis.
  4. Supporting detail #3 gives evidence and supports the thesis.
  5. Conclusion readdresses the thesis, wraps up the topic

When you write an expository essay, your voice is more formal because you are giving information.

It is alright to use the personal pronouns "I" and "me" if they are relevant to your presentation, as in the example below. Do not use the words "I" and "me" to interject an opinion as you do in a narrative essay.

You also want to avoid slang and abbreviated phrases, like "lol." You are imparting knowledge, so this is not a personal opinion you are sharing — it is facts, so you need to be more formal.

Take a look at the following example:

What is Addition?

Addition is taking two or more amounts and counting them all together. For example, if you had two apples and three apples, you would have five apples in all. Sometimes, we count things in order to see if we have enough to share with everyone. So, if six of your friends were at your house, you would not have enough apples to give each of them one whole apple.

Counting things in a collection can be lots of fun. You can see how many things you have collected and decide if you want to collect more. My dad collects stamps — he has 54 stamps from other countries and 68 stamps from the United States. To know how many he has in his collection, we must add 54 + 68.

  + 68


My dad has 122 stamps in his stamp collection. He has more stamps in his collection than his brother. We enjoy looking at his stamps and counting them when he gets new ones. That's why I love addition.

Did you notice that the essay is different from the outline?

When writing to explain something in math, your essay will be a little different.

If you are going to explain a concept, you will introduce that concept in the first paragraph. In the second paragraph, you will give explanations of how to do it. Use transition words, like "First," "Second," "Next," and "Last."

If you need an extra paragraph to finish explaining how to do it, place it next. In the last paragraph, you will wrap it all up by restating your main idea.

Continue on to the Got It? section, where you will practice doing these steps.

Image - Button Next