Lesson 1: Explore Relationships Between Two Variables6.AT.11

I can…

I can recognize when two quantities change together, and identify which one is the independent variable and which is the dependent variable.

Key words

• independent variable — The quantity that is subject to choice. It does not depend on the other quantity.
• dependent variable — The quantity that changes in response to the independent variable.
• depends on — One quantity depends on another when changing the first causes the second to change.
• quantity — Something that can be counted or measured.
• relationship — How two quantities change together.

Steps

1. The two quantities are hours of sunlight per day and average plant height after 3 weeks.
2. Akela CHOSE where to put each tray, so she chose the sunlight. Sunlight is subject to choice — that makes it the independent variable.
3. She did not choose how tall the plants got. Height responded. That makes height the dependent variable.
4. Say it as a sentence: plant height depends on sunlight.

Try it

A dog walker charges by the hour. Which sentence is correct?

Check your answer

The total charge depends on the number of hours, so hours is the independent variable.

The walker chooses how many hours to work; the money that results responds to that choice. Hours is subject to choice, so hours is independent and the total charge is dependent.

Sentence starter

I know ___ because ___.

Goal: I can explain which quantity depends on the other using the words independent variable, dependent variable, and depends on.