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LESSON PLAN
Writing and Evaluating Expressions
A
Apothem Team
Grade 8 · Algebra & Patterning
LESSON AT A GLANCE
Warm-up
5 min
Instruction
15 min
Guided practice
15 min
Independent work
12 min
Exit ticket
3 min
Warm-up
Write a number trick in words ('think of a number, double it, add 5') and have students record it as an expression.
Instruction
Guided practice
Independent work
Exit ticket
Students write, evaluate, and simplify expressions. Exit ticket: evaluate one expression for a given value.
TIP Insist on the order of operations during substitution — a common slip is to add before multiplying.
WORKED EXAMPLES
Write an expression for 'triple a number, then subtract 4'.
3x − 4.
Evaluate 2a + 5 when a = 6.
2(6) + 5 = 12 + 5 = 17.
MATERIALS
•Student notebooks
•Algebra tiles
•Practice worksheet (PDF)
•Board or projector
WATCH FOR
!Adding before multiplying during substitution — keep the order of operations in view.
!Combining unlike terms, such as 3x + 2 → 5x.