8.2 Small Group · Group 1

Tier 2 Intervention · Concrete-Representational-Abstract (CRA) · Dual-Language Anchors

Visual Models · Solve One-Step Addition and Subtraction Equations · Equation · Procedural Fluency

Name: Date: Period: Learning Goal:

■ CONCEPT SUMMARY & GUIDED NOTES: Let's build it together — How do I solve an addition or subtraction equation?

1Undo the operation with its inverse, and do it to both sides to keep the equation balanced.

To solve means to find the value that makes the equation true. I use the inverse operation (the opposite) to get the variable alone, and I do the same thing to both sides. We'll walk through a worked example, try one together, then you'll try a few with hints right there when you need them.

2Worked Example — Watch me

3Mathematical Word Bank

Solve One-Step Addition and Subtraction Equations (Resolver ecuaciones de suma y resta de un paso) — Use one inverse addition or subtraction operation to isolate the variable.
Equation (Ecuación) — A math sentence with an equal sign showing both sides are the same.
Inverse operation (Operación inversa) — Two math actions that undo each other, like × and ÷.
Isolate (Despejar) — To get the letter by itself on one side.
Solution (Solución) — A number that makes the equation or inequality true.
One-step equation (Ecuación de un paso) — An equation you can solve in a single step using one inverse operation.

4Watch out

A common mistake is applying the same operation instead of the inverse — for example, solving x − 7 = 15 by subtracting 7 from both sides (getting the wrong x = 8) instead of adding 7 to both sides (the correct x = 22). Another common mistake is doing the inverse operation to only one side, like solving x + 6 = 14 by subtracting 6 from the left but forgetting the right side. Before you submit, name the operation shown in the equation, choose its inverse, apply it to BOTH sides, and check by substituting your answer back into the original equation.

SECTION 1 CONCEPTUAL UNDERSTANDING & VISUAL MODELS [Visual Modeling]

1 NUMBER LINE

Use the number line to solve x + 8 = 20. Start at 20 and count back 8 to find x.
✏️ Workspace & Solution Steps
2 BALANCE SCALE

Algebraic Balance Model

Solve: m − 14 = 32
✏️ Workspace & Solution Steps

SECTION 2 REAL-WORLD CONTEXTS & PROBLEM SOLVING [Applications]

🗣️ MATHEMATICAL DISCOURSE & TALK MOVES SMP.3 / Construct Viable Arguments

Group Discussion Prompt: How does your visual model justify your mathematical solution?

🗣️ Partner A:
Partner A: "I modeled this by identifying the relationship and..."

👂 Partner B:
Partner B: "I agree with your step because the standard mathematical rule states..."

✍️ The Writing Revolution (TWR) · Sentence Expansion Because · But · So

Complete each sentence stem to demonstrate precise mathematical reasoning:

BECAUSE The ratio remains equivalent because both quantities are scaled by the exact same multiplicative factor.

BUT Two ratios may look similar, but inverting the order of terms fundamentally changes the comparison.

SO The recipe requires 3 parts flour to 2 parts water, so the unit rate is 1.5 cups of flour per cup of water.

📐 CER MATHEMATICAL PROOF MATRIX (CER 2.0) SMP.3 / Proof & Justification

Writing Task: Justify why your mathematical solution is accurate and complete.

C Claim

Starter: My mathematical claim is that the solution is...

E Evidence

Starter: The evidence from the model/table demonstrates that...

R Reasoning

Starter: This proves my answer because the standard mathematical definition of...

Student Mastery Self-Assessment:

1 · Need More Support

2 · Getting Closer

3 · Got It / Solid

4 · Master / Can Teach It