4.1 Small Group · Group 2
Tier 1 Extension · Non-Routine Synthesis · Misconception Traps · Rigorous CER Proofs
Understand Percent · Percent · 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.
- Students voted on a mascot, and 4 out of every 10 voters chose the tiger. I want to know how many that is out of 100.
- "4 out of every 10" is a ratio, so I write an equivalent ratio with 100 as the second term. Multiplying both terms by 10 gives 40 out of 100.
- On a decimal grid of 100 squares, I shade 40 squares — one square for each percent.
- 40 out of 100 is written 40%. So 40% of the students voted for the tiger.
- Shanice's gray kitten weighs 4 ounces. The orange kitten weighs 1.5 times as much. What percent of the gray kitten's weight is the orange kitten's weight?
- The gray kitten is the whole, so its weight is 100%.
- Draw a tape diagram: one full tape is 100%. The orange kitten needs 1.5 tapes — one whole tape plus half of another.
- One whole is 100% and half a whole is 50%, so 100% + 50% = 150%. The orange kitten weighs 150% of the gray kitten's weight — more than one whole, which matches it being the heavier kitten.
- 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 ___ ."
- Understand Percent (Comprender el porcentaje) — A percent is a ratio that compares a number to 100, so every percent answers the question “how many out of 100?”
- Percent (Porcentaje) — A ratio that compares a number to 100. The word means “per hundred,” and the symbol is %.
- Per hundred (Por cada cien) — The meaning hidden inside the word percent: for every group of 100. It is why every percent can be written as a fraction over 100.
- Decimal grid (Cuadrícula decimal) — A 10-by-10 grid of 100 squares. Shading squares shows a percent directly, one square per percent.
- Part-to-whole (Parte a todo) — A comparison of one part against the whole amount. In a percent, the whole is always 100%.
- Greater than 100% (Mayor que 100 %) — More than one whole. A percent above 100 means the amount is larger than the thing it is being compared to.
- A common mistake with percent is scaling only one term of the ratio: reading 7 out of 10 as 7%. A percent compares to 100, so BOTH terms must be multiplied by the same factor — 10 × 10 = 100, so 7 × 10 = 70, giving 70%. Reading it as 7% describes seats that are nearly empty when they are nearly full. A second mistake is treating a percent as an amount: 150% of a 200-point goal is 1.5 × 200 = 300 points, not 150 points.
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1 MATCHING GAME
Match each comparison to its percent.
- 4 out of 10
- 23 out of 100
- 1.5 times the whole
- the whole itself
- A40%
- B23%
- C150%
- D100%
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2 FILL TABLE
Write each ratio as an equivalent ratio out of 100, then as a percent.
Ratio Out of 100 Percent 4 out of 10 7 out of 20 3 out of 4 ✏️ Scratchpad / Reasoning
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3 MULTIPLE CHOICE
Which is exactly one whole?
- A100%
- B50%
- C10%
- D1%
✏️ Workspace & Solution Steps -
4 MULTIPLE CHOICE
A recipe makes 200% of what you need. That means it makes…
- ATwice as much as you need
- BHalf of what you need
- CExactly what you need
- DTwo servings total
✏️ Workspace & Solution Steps -
5 MULTIPLE CHOICE
In Mr. Alvarez's class 40% of 30 students play an instrument. In the chess club 60% of 15 members do. Which group has MORE musicians?
- AThe class, 12 against 9
- BThe chess club, because 60% is greater than 40%
- CThey tie, because both are close to half
- DYou cannot compare percents of different-sized groups
✏️ Workspace & Solution Steps -
6 MULTIPLE CHOICE
Nadia finds 30% of 60 by taking 10% three times: 6, 12, 18. Owen halves 60 to get 50%, then subtracts 20%. Whose method reaches 30% of 60?
- AOnly Nadia — 10% three times is exactly 30%
- BBoth, because 50% − 20% = 30%
- COnly Owen — benchmarks are faster than repeating 10%
- DNeither — 30% of 60 cannot be found with benchmarks
✏️ Workspace & Solution Steps
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.