Algebraic Expressions Lesson 4

Using Negative and Decimals as Values for Algebraic Symbols

Haleemah and ET work to model a scooter trip by relating the scooter’s start location, trip time, velocity, and end location. Using this context, they begin to think about the different kinds of values that an algebraic symbol can take on.

Episode 1: Making Sense

ET and Haleemah make sense of the scooter applet and create a conjecture for the relationship between velocity, trip time, starting location, and ending location.

Episode 2: Making Sense

The students continue exploring the scooter applet and see if their conjecture holds for negative and decimal values. 

Episode 3: Exploring

ET and Haleemah apply their method for finding the scooters ending location and discover a mistake.

Episode 4: Repeating Your Reasoning

The students apply their method for finding the ending location for a scooter trip that starts at 4 meters and lasts for 3 seconds to two more trips with different velocities. 

Episode 5: Exploring

Haleemah and ET generalize their method and write an algebra equation that relates the scooter’s velocity and its end location.

Episode 6: Reflecting

ET and Haleemah reflect on their generalized algebraic expression and think about what would happen if their variable, v, was a negative number.

Episode 7: Reflecting

ET and Haleemah reflect on their generalized algebraic expression and think about the values their variable could represent.