3.3 Small Group · Group 2
Tier 1 Extension · Non-Routine Synthesis · Misconception Traps · Rigorous CER Proofs
Ratio Tables · Ratio table · Procedural Fluency · Reasoning & Critique
- 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.
- The pancake recipe is 2 cups of mix for every 3 cups of milk, so the ratio is 2:3.
- To make 2 batches, my scale factor is 2.
- I multiply both numbers by 2: 2 x 2 = 4 cups of mix, and 3 x 2 = 6 cups of milk.
- Now my row is 4:6, which is the same ratio as 2:3.
- I do NOT add 2 to each number; I multiply both by the same factor.
- A drink uses 1 cup of juice for every 4 cups of water, so the ratio is 1:4.
- To double it, what scale factor do we use? We use 2.
- Multiply both by 2: 1 x 2 = 2 cups of juice and 4 x 2 = 8 cups of water, giving 2:8.
- 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 ___ ."
- Ratio Tables (Tablas de razones) — Tables that organize pairs of equivalent ratios.
- Ratio table (Tabla de razones) — A table of equal ratios that shows a pattern.
- Equivalent ratio (Razón equivalente) — Two ratios that mean the same thing, like 1:2 and 2:4.
- Scale factor (Factor de escala) — The number you multiply both parts of a ratio by to get an equal ratio.
- Pattern (Patrón) — A rule that numbers follow again and again.
- Additive pattern (Patrón aditivo) — Building new rows of a ratio table by adding each column's own constant amount, so the two columns grow together.
- A common mistake in Ratio Tables is scaling only ONE part of the ratio, or adding the scale factor to a part instead of multiplying by it — for example, turning 2:3 into 6:3 (multiplying only the first number by 3 and forgetting the second) or into 4:5 (adding the scale factor 2 to the second number instead of multiplying, since 3+2=5 but 3×2=6). Before you submit, multiply BOTH numbers by the same scale factor and check that your new ratio simplifies back to the original.
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1 FILL TABLE
Complete the ratio table for lemon juice to water in Chef Reyes's lemonade recipe (1 cup lemon juice for every 4 cups water).
Pitchers Lemon Juice (cups) Water (cups) 1 2 5 10 ✏️ Scratchpad / Reasoning -
2 DRAG SORT
Which rows belong in a ratio table for 3:4? Sort them into correct and incorrect.
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3 MULTIPLE CHOICE
The food truck sells tacos at a steady rate: 2 tacos cost $5. At that rate, how much do 6 tacos cost?
- A$15
- B$11
- C$12
- D$30
✏️ Workspace & Solution Steps -
4 MULTIPLE CHOICE
A smoothie recipe at the truck uses 4 cups of mango for every 3 cups of pineapple. How many cups of mango are needed for 9 cups of pineapple?
- A12
- B10
- C13
- D9
✏️ Workspace & Solution Steps
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5 OPEN RESPONSE
A recipe uses 4 cups of flour for every 3 cups of sugar. A student filled in a ratio table: 4:3, 8:6, 12:9, 14:12. Find and fix the error in the last row. Explain what went wrong.
✏️ Mathematical Justification & Response -
6 ERROR ANALYSIS
Level 2 Extension — Catch the Food Truck Error
- 1Read the order:The hot sauce mix uses a ratio of 2 spoons of pepper to 5 spoons of tomato (2:5). Find an equivalent row for a bigger batch.
- 2Pick a scale factor:To make the batch bigger, Maya picks a scale factor of 3. A scale factor should multiply BOTH parts.
- 3Scale the pepper:2 + 1 = 3 spoons of pepper
- 4Scale the tomato:5 + 1 = 6 spoons of tomato
Which step contains the error? Explain the mathematical misconception and write the correct calculation below.
✏️ Corrected Mathematical Work & Explanation
Group Discussion Prompt: How does your visual model justify your mathematical solution?
Partner A: "I modeled this by identifying the relationship and..."
Partner B: "I agree with your step because the standard mathematical rule states..."
Complete each sentence stem to demonstrate precise mathematical reasoning:
Writing Task: Justify why your mathematical solution is accurate and complete.