### Description

The lesson details how to solve mathematical equations when a variable can be substituted with an actual value. The lesson has students solve the same expression several times and substituting a different value for the variable each time. The lesson also reminds students to use the correct order of operations to solve the problems once they replace the variables with numbers. Relevant vocabulary, like simplify and substitute, is included in the lesson.

### Classroom Instruction:

- Begin by explaining to students that they have learned about variables having unknown values, but now they are going to learn how to plug in different values to evaluate expressions.
- While reading the content pages, reinforce previous vocabulary and give students additional examples of substitution and evaluation problems in order to help them practice the new algorithm. Use the additional resources to enhance understanding.
- Introduce the notes on evaluating expressions. Have students practice problems with and without two variables. Use the additional resources to enhance understanding.
- Have students practice problems by creating their own values for the variables to increase engagement in the classroom.
- Follow Activity page with students. Students should work in groups of three. Each student in the group should be assigned A, B, or C Have students begin by working individually to solve the answer for their letter. The group should then add all three answers for a final total. The total should be brought to the teacher to be checked for accuracy, if they are correct they can pick up the next round, if not, they must go back and work their problems again but this time collectively to see where the mistake was made. Once students have completed all the rounds, they are done!
- Distribute Practice page. Check and review the students’ responses as a class.
- Distribute the Homework page. Review student answers at the beginning of the next class to check for understanding.
- In closing, ask students to explain why a variable can have different numeric values.
- Allow for responses and discussion.

**Common Core State Standards: **

None for Grade 4, None for Grade 5, CCSS.Math.Content.6.EE.A.2, CCSS.Math.Content.6.EE.A.5

**Class Sessions (45 minutes): 1 class session**

**Additional Resources: **

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