Identifying Algebraic Expressions

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Objective

SWBAT identify the parts of an algebraic expression.

Big Idea

Students learn the vocabulary needed to discuss algebraic expressions.

Do Now

10 minutes

Students previously worked on performing the order of operations. The Do Now is a review of this concept.  Students may have difficulty with the second problem due to the nested parentheses.

Do Now

1.   Simplify [1 + (8 – 5)3] / 4

2.   Simplify 4 x ((2 - 2) / 2 / (9 - 1)+3)

 

After 10 minutes I will randomly select students to come up to the board and complete a step.  This may cause a lot of discussion depending on if students performed the order of operations correctly.  

  

   

   

Mini Lesson

15 minutes
This lesson's focus is the introduction of algebra and the pertinent vocabulary. I will post and discuss the definition of each term.  Then, I will present students with the example and we will identify the constant, variable, and coefficient.
Example 1: 4x + 7
A constant is a fixed value, a number on its own, whose value does not change.  A constant may either be positive or negative.
Based on the definition, what is the constant in this example?  How do you know 7 is the constant?

variable is any letter or symbol that represents a changeable or unknown value.

Based on the definition, what is the variable in this example?  Do we know what x is?

A coefficient is the number multiplied by the variable.  It is located in front of the variable.

Based on the definition, what is the coefficient in this example? Why is the coefficient 4?

Terms may consist of variables and coefficients, or constants. Terms are separated by the plus or minus signs.

How many terms does the example have?  What are the terms?

An algebraic expression is one or more algebraic terms in a phrase. It can include variables, constants, and operating symbols, such as plus and minus signs. It's only a phrase, not the whole sentence, so it doesn't include an equal sign.

 Is this an algebraic expression? Why?

Group Work

20 minutes

Each student will receive an Identifying Epressions Worksheet.  I will complete the first row with the class, so they understand how to complete the worksheet. They will complete the rest of the worksheet with their group.  Students should have the lesson's vocabulary in front of them as they work.  

Students may have difficulty with:

- Terms where the coefficient is 1, but the 1 is not visible.

- Terms that have fractions as coefficients.

- Expressions that don't have a constant.

After about 10 minutes, I will assign each group a row to present to the class.  Students should explain their answers and how they used the definitions to help them.

Exit Ticket

5 minutes

It is important to assess students' understanding of the lesson, independent of their group; so they will complete an Identifying Algebraic Expressions Exit Ticket.  The exit ticket is similar to the table that students completed with their group.

I will use the exit ticket to determine future lessons and how students should be grouped.