The Falling Glow Stick activity from Dan Meyer’s Three-Acts Math tasks , shows two video clips. The first video clip is from a movie where they drop a glow stick into a chasm to see how deep it is. And the second video reveals how the estimated height they arrived at, given the amount of seconds it took for the glow stick to reach the bottom. The activity can be found at the following website:
http://mrmeyer.com/threeacts/fallingglowsticks/

This activity address common core high school Algebra standard A-CED:
Creating equations that describe numbers or relationships.
Specifically this problem uses standard 2 of A-CED:
Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales.

To have students accomplish learning objectives in this standard, I would personally show students video one. I would proceed by having them estimate a guess and an interval for their guess: stating a height that is too high and a height that is too low.
To build upon their previous knowledge I would have students turn to their peers and collaborate about what variables and factors affect deriving the height of the chasm. I would walk around and prompt the students to use mathematical terminology such as rate, time, and distance.
Once finished with brainstorming and discussing with their peers, I would then challenge the students by having them build an equation on their own using the variables and factors from their discussion and encourage them to use their estimated interval to check their equation.
I would then show the second video where the solution is revealed. I would have the students check their solution and revise their equation based on the known variables if needed. During this time I will be walking around the room and formally assessing if students were able to create an equation that accurately expressed the relationship between the variables. If enough students grasp the concept, then I would have the class reflect upon their equation and ask them the last question given on Dan Meyer’s activity: if you drop a rock off of the Golden Gate Bridge, how long will it take for you to hear a splash? This will ensure that students have a general solution they can apply to other real world situations. If the students were struggling I would have a few students who had a good grasp of the activity explain their findings to the class. Based on their input, as a class, we would derive an equation together through guided instruction. The students would be able to use the answer from the second video to check their progress and accuracy of the equation. Once all students have a valid equation, I will proceed to ask them the question posed by Dan Meyer’s as previously mentioned.
To wrap up the activity I would have the students again gather in groups to compare their equations. For their benchmark assessment, as a group they must come to a consensus the best equation and graph the equation they agreed derived the most accurate solutions. The graphs must be scaled correctly with accurate units and axis. The students must present their graphs to the class and explain why their equation graph is valid and justify how it can be used in real world scenarios. On the back of the graph I would have the students write their equation and write their explanation and justification.