6.11 Small Group · Group 2
Second Challenge Form · Non-Routine Extension · Same Standard, New Problems
Fraction Division Problem Solving · Model · Procedural Fluency · Real-World Applications
- You already can do this. So we go up a level, not up a number: find what is always true, show it a second way, and be ready to defend it with a reason instead of an answer.
- Agent Torres has 2/3 gallon of dust and each test uses 1/6 gallon. I ask: how many tests fit?
- The total 2/3 is the dividend. The size of each test 1/6 is the divisor. My equation is 2/3 ÷ 1/6.
- Keep 2/3, change to ×, flip 1/6 to 6/1: 2/3 × 6/1 = 12/3 = 4.
- So she can run 4 tests. I check by multiplying back: 4 × 1/6 = 4/6 = 2/3. It matches the total, so the answer is reasonable.
- A ribbon is 3/4 yard and each bow uses 1/4 yard. The total 3/4 is the dividend; 1/4 is the divisor.
- Equation: 3/4 ÷ 1/4. Keep, change, flip: 3/4 × 4/1 = 12/4 = 3.
- So we can make 3 bows. Check: 3 × 1/4 = 3/4. It matches, so it is reasonable.
- Now prove it: say why that move had to work at all — not just that it did.
- Sentence frame — convince a skeptic: "My method works because ___ . It would stop working if ___ ."
- Fraction Division Problem Solving (Resolución de problemas de división de fracciones) — Use fraction division to find an unknown number of groups or the size of each group.
- Model (Modelo) — A picture or math way to show a problem so you can solve it.
- Equation (Ecuación) — A math sentence with an equal sign showing both sides are the same.
- Solution (Solución) — A number that makes the equation or inequality true.
- Reasonableness (Razonabilidad) — Checking if your answer makes sense.
- Inverse operations (Operaciones inversas) — Two math actions that undo each other, like × and ÷.
- A common mistake in Fraction Division Problem Solving is reversing which fraction is the dividend and which is the divisor when setting up the equation from a word problem. For example: a pitcher holds 3/4 cup of punch, and each serving is 1/8 cup — how many servings? The correct setup is total ÷ group size = 3/4 ÷ 1/8 = 3/4 × 8/1 = 24/4 = 6 servings. A student who reverses the setup calculates 1/8 ÷ 3/4 = 1/8 × 4/3 = 4/24 = 1/6, an answer smaller than 1 that can't possibly be a serving count. Before you submit, check: does my answer make sense as a NUMBER OF GROUPS? If the setup gives a fraction less than 1 for a 'how many' question, you likely swapped the dividend and divisor.
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1 MULTIPLE CHOICE
A ribbon is 4/5 of a yard long. Each bow uses 1/10 of a yard. Which equation finds how many bows can be made?
- A4/5 ÷ 1/10
- B1/10 ÷ 4/5
- C4/5 × 1/10
- D4/5 + 1/10
✏️ Workspace & Solution Steps -
2 MULTIPLE CHOICE
A detective has 1/2 gallon of solution. Each test uses 1/8 gallon. How many tests can be run?
- A4
- B1/16
- C16
- D1/4
Rewrite each fractionWork it outSimplify -
3 MULTIPLE CHOICE
Marcus solved 2/3 ÷ 1/4 and got 8/3 = 2 2/3. He says 'That can't be right because I started with less than 1.' Is Marcus's math correct? Is his reasoning correct?
- AHis math is correct (2 2/3), but his reasoning is wrong — dividing by a small fraction gives a larger result
- BHis math and reasoning are both correct — the answer should be less than 1
- CHis math is wrong — the answer should be 1/6
- DHis math is wrong — the answer should be 8/12
✏️ Workspace & Solution Steps
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4 ERROR ANALYSIS
Fix our table's thinking
- 1The problem:Room 1 — Evidence Locker: Agent Torres has 7/8 pound of casting clay to lift footprints. Each cast uses 1/8 pound. How many casts can she make to unlock the door?
- 2A classmate at our table answered:6
Which step contains the error? Explain the mathematical misconception and write the correct calculation below.
✏️ Corrected Mathematical Work & Explanation -
5 ERROR ANALYSIS
Spot the Common Mistake
- 1Problem:A chemist has 3/4 liter of solution. Each test tube holds 1/8 liter. How many test tubes can be filled?
- 2Student's equation:3/4 ÷ 1/8 = 3/4 × 1/8
- 3Solve:3/4 × 1/8 = 3/32
- 4Answer:3/32 of a test tube
Which step contains the error? Explain the mathematical misconception and write the correct calculation below.
✏️ Corrected Mathematical Work & Explanation -
6 ERROR ANALYSIS
Find the Problem-Solving Error
- 1Problem:A tank has 3/4 gallon of water. Each bucket holds 1/6 gallon. How many buckets can be filled?
- 2Student's equation:1/6 ÷ 3/4
- 3Solve:1/6 × 4/3 = 4/18 = 2/9
- 4Answer:2/9 buckets
Which step contains the error? Explain the mathematical misconception and write the correct calculation below.
✏️ Corrected Mathematical Work & Explanation
Writing Task: Justify why your mathematical solution is accurate and complete.