Code Breaker Slides Mission: Math Review
SECRET CODE
SUBSTITUTION
Cracking the code by replacing letters with numbers.
Level 1: Expressions
Level 2: Equations
Level 3: Systems
Mission Checklist
1
The Swap
Take the letter out. Put the number in. (Use Parentheses!)
2
The Solve
Follow GEMDAS (Grouping, Exponents, Mult/Div, Add/Sub).
3
The Final Code
Write your final answer clearly.
Level 1: Expressions
RANK: NOVICE
Target Expression:
5x + 10
x = 4
1
Replace x with 4
5(4) + 10
2
Multiply 5 × 4
20 + 10 = 30
Level 2: Equations
RANK: AGENT
PROBLEM: DOES IT FIT THE CODE?
2m - 5 = 11
→
m = 8
STEP 1: PLUG IT IN
2(8) - 5 = 11
STEP 2: CHECK THE MATH
16 - 5 = 11
11 = 11? YES! Code Verified.
Level 3: Systems
RANK: ELITE CRACKER
TWO-PART CODE:
y = 2x + 1
3x + y = 11
1. FIND THE EQUAL
One letter is equal to a whole expression!
2. THE BIG SWAP
Replace y with (2x + 1)
3. NEW CODE
3x + (2x + 1) = 11
Cracking the Elite Code
1. Combine
3x + 2x + 1 = 11
5x + 1 = 11
2. Isolate
5x = 11 - 1
5x = 10
x = 2
3. Find Y
y = 2(2) + 1
y = 4 + 1
y = 5
Solution: (2, 5)
Pro Agent Tips
Use ()
Always put parentheses around the number or expression you are plugging in!
Calculator
Double-check your arithmetic after the substitution. Don't let simple math blow your cover!
Substitution Mission Worksheet Mission: Substitution
8th Grade Math Review • Protocol 8.EE.C.8.B
Name: ______________________
Agent Checklist
I found the value of the variable.
I used parentheses ( ).
I multiplied before adding.
I checked with a calculator.
Level 1: Novice Expressions
1. Evaluate: 3x + 7 x = 5
Result:
2. Evaluate: 10 - 2y y = 3
Result:
3. Evaluate: 4m + 12 m = 2
Result:
Level 2: Agent Equations
4. Is b = 6 the solution for:
Verdict
TRUE
FALSE
5. Is n = 5 the solution for:
Verdict
TRUE
FALSE
Level 3: Elite Systems
Elite Protocol: Substitution
y = 3x
Step 1: The Big Swap
2x + (_____) = 20
Step 2: Solve for X
x = _______
Step 3: Solve for Y
Use X to find Y. Plug into: y = 3x
y = _______
Final Solution Point
(
x
,
y
)
Level 3: Elite Practice
y = 2x
Show Work Area
Final Solution
( __ , __ )
Mission Debrief
Why do we use parentheses ( ) when substituting a number into a secret math code?
Substitution Teacher Guide Teacher Guide: Secret Code Substitution
Lesson Context: 8th Grade SPED Review (Expressions, Equations, Systems)
SPED Scaffolding Strategies
Visual Anchors
Frame variables as "locked codes." Encourage students to physically cross out letters and write numbers above them.
Parentheses Rule
Insist on 5(x) to prevent them from seeing "5" and "4" as "54" during substitution. This clarifies the multiplication operation.
Answer Key
Level 1
3(5) + 7 = 15 + 7 = 22
10 - 2(3) = 10 - 6 = 4
4(2) + 12 = 8 + 12 = 20
Level 2
4(6) - 10 = 14 → 24 - 10 = 14 → True (14 = 14)
5(5) + 8 = 33 → 25 + 8 = 33 → True (33 = 33)
Level 3
System 6: y = 3x, 2x + y = 20
2x + (3x) = 20 → 5x = 20 → x = 4; y = 3(4) = 12 → (4, 12)
System 7: y = 2x, 5x + y = 14
5x + (2x) = 14 → 7x = 14 → x = 2; y = 2(2) = 4 → (2, 4)
Common Pitfalls
Operational Order: Students often add before multiplying. Multiply first!
Negative Values: Use parentheses to avoid losing signs (e.g., 5(-2) vs 5-2).
System Confusion: Remind them that a solution is a "Coordinate Pair."
Pacing: 10m Slides, 20m Worksheet, 10m Practice, 5m Exit Ticket
CCSS.MATH.CONTENT.8.EE.C.8.B
Substitution Mission Condensed Worksheet Mission: Substitution
8th Grade Math Review • Protocol 8.EE.C.8.B
Name: ______________________
Found variable value.
Used parentheses ( ).
Multiplied first.
Checked calculator.
Level 1: Novice Expressions
1. Evaluate: 3x + 7 x = 5
Answer:
2. Evaluate: 10 - 2y y = 3
Answer:
3. Evaluate: 4m + 12 m = 2
Answer:
Level 2: Agent Equations
4. Is b = 6 the solution for:
TRUE
FALSE
5. Is n = 5 the solution for:
TRUE
FALSE
Level 3: Elite Systems
Elite Protocol: Substitute the expression into the other equation.
y = 3x
Step 1: The Big Swap
2x + (_____) = 20
Step 2: Solve for X
x = _______
Step 3: Solve for Y (Plug X into y = 3x)
y = _______
Final Solution Point
(
x
,
y
)
Level 3 Practice: Independent Mission
y = 2x
Step 1 & 2: The Swap & Solve X
Step 3: Solve for Y
Final Solution
(
x
,
y
)
Mission Debrief
Why do we use parentheses ( ) when substituting a number into a secret math code?
