Lesson: Values Can Be Substituted for Variables
Class set of white boards
Attached Substitution Matching Game
Attached Substitution Notes Overhead
Attached Substitution Notes student copies
8-12A 1.0 Students identify and use the arithmetic properties of subsets of integers and rational, irrational, and real numbers, including closure properties for the four basic arithmetic operations where applicable:
A1.1 Students use properties of numbers to demonstrate whether assertions are true or false.
Launch: Present 3 problems that review recently acquired skills, provide 3-5 minutes for solving, solicit answers, guide student-led clarification if needed
Write on the board: Variable, Value, Substitute
Solicit prior knowledge about the meaning of these terms. If students can give an example, write it on the board beside the words. Remind students that when things are equal, they can do the same job. So if a value and a variable are equal, they can take each other’s place and we will still get the same result. If they can’t do the same job, then they are not equal.
Lead students through note-taking on their photocopies of the attached Student Note Worksheet. The definition and application of the term “substitute” are written on the attached Substitute Overhead. Model substitution by opening a parenthesis in the place of the variable every time. This prevents confusion in cases of multiplication and helps students keep terms visually organized.
If students fail Exit Ticket, or if they are struggling with substitution after Guided Practice, attached are numerous worksheets and some additional overheads to provide additional exposures to the process. Students should move from replacing the variable to simplifying the terms .
After several models, students complete both sides of the attached Notes worksheet. This will be checked for progress, but should stay in students’ binders for future reference.
As students are showing proficiency, ask 1-3 students to rewrite their work on the board as an example for other students.
Print, copy, cut up and mix pieces of attached Substitution Matching Game. Distribute white boards to each student. In pairs, students try to match the solutions to the problems by checking with substitution. Make a transparency of the original game sheet so that you can project the answers once students finish.
Students complete attached worksheet independently.
Substitute and simplify.
2x + 15 if x = 6
Scale 1 - 5