## 1. Know - Understand - Do Organizer

• Topic:Variables
• Subject(s):Science
• Days:30

Which standards are students learning in this unit?
Know:

Pendulums and Variables - (Investigation 1 - Swingers)
pendulum
cycle
variable
standard
controlled experiment
two-coordinate graph

Variables in an Experiment - (Investigation 2 - Lifeboats)
capacity
independent variable

Systems and Controlled Experiments - (Investigation 3 - Plane Sense)
system

Systems, Energy, and Controlled Experiments - (Investigation 4 - Flippers)
multiple trials

Understand:

Pendulums and Variables - (Investigation 1 - Swingers)
A pendulum is a mass, suspended on a pivot point, free to swing.
A variable is anything that you can change in an experiment that might affect the outcome.
In a controlled experiment all variables are controlled except one, allowing the experimenter to observe the effect of that one variable on the outcome.
The length of a pendulum determines the number of swings in a unit of time.
Graphs can be used to display results, look for experimental errors, and make predictions.

Variables in an Experiment - (Investigation 2 - Lifeboats)
A variable is anything that you can change in an experiment that might affect the outcome.
Capacity is the maximum volume of fluid a container can hold.
In a controlled experiment, all the variables are controlled except one, allowing the experimenter to observe the effect of that one variable on the outcome.
A two-cordinate graph displays the relationship between the independent and dependent variables in an experiment.
The larger the capacity of a boat, the greater the number of passengers it can hold.

Systems and Controlled Experiments - (Investigation 3 - Plane Sense)
A system is a set of related objects that can be studied in isolation.
A variable is anything that you can change in an experiment that might affect the outcome.
In a controlled experiment all the variables are controlled except one, allowing the experimenter to observe the effect of that one variable on the outcome.
A two-coordinate graph displays the effect of a variable on a system.

Systems, Energy, and Controlled Experiments - (Investigation 4 - Flippers)
A system is a set of related objects that is working together.
A variable is anything you can change in an experiment that might affect the outcome.
In a controlled experiment all the variables are controlled except one, allowing the experimenter to observe the effect of that one variable on the outcome.
Conducting multiple experimental trials adds validity to results.
Graphs can be used to demonstrate the relationship between an experimental variable and the results.

Do:

Pendulums and Variables - (Investigation 1 - Swingers)
Observe and compare the behaviors of pendulums.
Gain experience with the concept of variable.
Conduct controlled experiments to find out what variables affect the number of cycles a pendulum will complete in a unit of time.
Relate pendulum length to the number of cycles it completes in a unit of time.
Make concrete, pictorial, and two-coordinate graphs of experimental results.
Use graphs to look for errors and make predictions.
Use scientific thinking processes to conduct investigations and build explanations.

Variables in an Experiment - (Investigation 2 - Lifeboats)
Identify variables that might affect the number of passengers (pennies) a paper-cup boat can hold without sinking.
Measure the capacity of paper-cup boats in metric units.
Conduct controlled experiments.
Graph the results of experiments and use the graph to make predictions.
Relate the capacity (displacement) of a boat to the number of passengers it can hold.

Systems and Controlled Experiments - (Investigation 3 - Plane Sense)
Observe and compare the characteristics of model-plane flight.
Identify variables that might affect the flight of a model plane.
Relate the length of flight to the number of winds on a rubber band powering a propeller.
Design and conduct controlled experiments.
Create graphs to look for relationships between variables and the flight of model planes.

Systems, Energy, and Controlled Experiments - (Investigation 4 - Flippers)
Observe and compare the behavior of model catapults.
Explore and identify the variables of the flipper system.
Measure the height and distance an object travels.
Design and conduct controlled experiments.
Compare results of their experiments to a standard launch.
Conduct multiple trials of the same variable and calculate averages of the outcomes.
Create two-coordinate graphs to display the results of experiments.