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 amount you choose. The other amount depends on it.
• dependent variable — The amount that changes when the other does.
• depends on — It changes when the other one changes.
• quantity — A number with a meaning, like 540 meters.
• relationship — How two amounts are linked.
• Table of values — A table that lists matching pairs of numbers.
• Input — The number you put in to start.
• Output — The number that comes out.

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 bakery sells muffins for the same price each. Which sentence is correct?

Check your answer

The total cost depends on the number of muffins bought, so the number of muffins is the independent variable.

The buyer chooses how many muffins to buy; the total cost responds to that choice. The number of muffins is subject to choice, so it is independent and the total cost 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.