9.1 Small Group · Group 2
Tier 1 Extension · Non-Routine Synthesis · Misconception Traps · Rigorous CER Proofs
independent variable · dependent variable · 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.
- The two quantities are hours of sunlight per day and average plant height after 3 weeks.
- Akela CHOSE where to put each tray, so she chose the sunlight. Sunlight is subject to choice — that makes it the independent variable.
- She did not choose how tall the plants got. Height responded. That makes height the dependent variable.
- Say it as a sentence: plant height depends on sunlight.
- Claire burned 123 Calories on a 30-minute jog and 246 Calories on a 60-minute jog.
- Which did Claire choose — the minutes, or the Calories?
- She chose how long to jog. So time is independent, and Calories burned is dependent.
- Sentence frame: ___ depends on ___ .
- 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 ___ ."
- independent variable (variable independiente) — The quantity that is subject to choice. It does not depend on the other quantity.
- dependent variable (variable dependiente) — The quantity that changes in response to the independent variable.
- depends on (depende de) — One quantity depends on another when changing the first causes the second to change.
- quantity (cantidad) — Something that can be counted or measured.
- relationship (relación) — How two quantities change together.
- Naming the variables backward — calling the responding quantity 'independent' because it is the one the question asks about.
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1 MULTIPLE CHOICE
Two quantities are related. Which statement is ALWAYS true?
- AThe independent variable is subject to choice
- BThe independent variable is always the larger number
- CThe dependent variable is always measured in dollars
- DThe independent variable is always listed first in a table
✏️ Workspace & Solution Steps
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2 MULTIPLE CHOICE
Which question would you ask to find the DEPENDENT variable?
- AWhich quantity responds when the other one changes?
- BWhich quantity is larger?
- CWhich quantity has units?
- DWhich quantity comes first alphabetically?
✏️ Workspace & Solution Steps -
3 MULTIPLE CHOICE
Claire decides to walk instead of jog for the same 30 minutes. What happens to the two variables?
- ATime stays the independent variable; Calories burned still depends on it
- BCalories burned becomes the independent variable
- CNeither is a variable any more
- DTime becomes the dependent variable
✏️ Workspace & Solution Steps -
4 MULTIPLE CHOICE
If Claire runs exactly 3 miles and records how long it takes, which is the independent variable now?
- ADistance (3 miles)
- BTime it takes
- CHer speed
- DCalories burned
✏️ Workspace & Solution Steps -
5 MULTIPLE CHOICE
Claim: “The dependent variable always has the larger values.” Is this claim always, sometimes, or never true?
- ASometimes — the size of the numbers has nothing to do with which variable is which
- BAlways — the dependent variable is the result, so it is bigger
- CNever — the independent variable is always the larger one
- DOnly when both quantities are measured in the same unit
✏️ Workspace & Solution Steps
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6 OPEN RESPONSE
A pizza shop decides each morning how many pizzas to make, then weighs out the cheese it needs. Devon says: “Cheese is the independent variable, because the shop buys the cheese before it makes any pizzas.” Devon is wrong. What rule did Devon use, and why does that rule fail here?
✏️ Mathematical Justification & Response
Complete each sentence stem to demonstrate precise mathematical reasoning:
Writing Task: Justify why your mathematical solution is accurate and complete.