6.AT.8 Lesson 8-3-group1 🟡 Group 1 · Set B
MASTERY CHECK
☐ Exceeds☐ Meets Target☐ Needs Practice

8.3 Small Group · Group 1

Second Practice Form · Re-Teach, Homework or Retake · Same Standard, New Problems

Solve Multiplication and Division Equations · Inverse operation · Procedural Fluency · Reasoning & Critique

Interactive Workbench & Models →
Name: Date: Period: Learning Goal:
■ CONCEPT SUMMARY & GUIDED NOTES: Let's build it together — How do I solve a multiplication or division equation?
1Divide to undo multiplying, and multiply to undo dividing — always on both sides.
  • When a variable is multiplied or divided by a number, I use the inverse operation to get it alone. Division undoes multiplication, and multiplication undoes division. 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
  1. Solve 3x = 21. This means 3 times x equals 21.
  2. The inverse of multiplying by 3 is dividing by 3.
  3. I divide both sides by 3: 3x ÷ 3 = 21 ÷ 3.
  4. That leaves x = 7. Check: 3 × 7 = 21. True!
3Mathematical Word Bank
  • Solve Multiplication and Division Equations (Resolver ecuaciones de multiplicación y división) — Use inverse multiplication or division to isolate the variable.
  • Inverse operation (Operación inversa) — Two math actions that undo each other, like × and ÷.
  • Multiply (Multiplicar) — To add equal groups again and again.
  • Divide (Dividir) — To split into equal groups.
  • Isolate (Despejar) — To get the letter by itself on one side.
  • Coefficient (Coeficiente) — The number in front of a letter, like the 3 in 3x.
4Watch out
  • A common mistake in Solve Multiplication and Division Equations is applying the SAME operation again instead of the inverse — for example, seeing 6x = 42 and multiplying both sides by 6 to get x = 252, instead of dividing by 6 to get x = 7. Before you submit, ask: did I use the OPPOSITE operation shown in the equation, and did I apply it to both sides?
SECTION 1 REAL-WORLD CONTEXTS & PROBLEM SOLVING [Applications]
  1. 1 MULTIPLE CHOICE

    A detective splits 54 clues equally among 9 case files. The equation 9c = 54 represents this. What is c?

    1. Ac = 6
    2. Bc = 63
    3. Cc = 45
    4. Dc = 9
    ✏️ Workspace & Solution Steps
  2. 2 MULTIPLE CHOICE

    Vault A is sealed with 4x = 32. Crack the lock: what is x?

    1. Ax = 8
    2. Bx = 128
    3. Cx = 28
    4. Dx = 36
    ✏️ Workspace & Solution Steps
  3. 3 MULTIPLE CHOICE

    Vault B is sealed with x / 3 = 6. Crack the lock: what is x?

    1. Ax = 18
    2. Bx = 2
    3. Cx = 9
    4. Dx = 3
    ✏️ Workspace & Solution Steps
  4. 4 MULTIPLE CHOICE

    Vault C is sealed with 5n = 45. Crack the lock: what is n?

    1. An = 9
    2. Bn = 225
    3. Cn = 40
    4. Dn = 50
    ✏️ Workspace & Solution Steps
SECTION 2 MATHEMATICAL WRITING & ERROR ANALYSIS [Reasoning & Critique]
  1. 5 ERROR ANALYSIS

    Spot the Common Mistake

    1. 1Equation:6x = 42
    2. 2Choose operation:To undo it, I will multiply both sides by 6.
    3. 3Apply to both sides:6x × 6 = 42 × 6
    4. 4Simplify:x = 252

    Which step contains the error? Explain the mathematical misconception and write the correct calculation below.

    ✏️ Corrected Mathematical Work & Explanation
  2. 6 ERROR ANALYSIS

    Level 2 Extension - The Vault That Won't Open

    1. 1Equation:4x = 32
    2. 2Identify inverse:Inverse of multiplication is multiplication
    3. 3Apply to both sides:4x x 4 = 32 x 4
    4. 4Simplify:x = 128

    Which step contains the error? Explain the mathematical misconception and write the correct calculation below.

    ✏️ Corrected Mathematical Work & Explanation
📐 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