The 3-acts math task, “Taco Cart,” by Dan Meyer can be found at http://threeacts.mrmeyer.com/tacocart/

and is aligned to

• CCSS-Math 8.G.7 Apply the Pythagorean Theorem to determine unknown side lengths in right triangles in real-world and mathematical problems in two and three dimensions,
• CCSS-MATH F-IF.4 For a function that models a relationship between two quantities, interpret key features of graphs and tables in terms of the quantities, and sketch graphs showing key features given a verbal description of the relationship.
• CCSS-Math MP.4 Model everyday problems with mathematics.

The first act shows a video introduces the problem which is that Dan and Ben are on the beach when they notice a taco cart on the street. Ben wants to walk straight over (through the sand) and Dan wants to walk toward the street and then straight to the taco car down the street because they walk a lot slower on the sand, so they go their separate ways. The second act provides pictures of the path Ben and Dan each take with the dimensions as well as the walking speed on the sand and the walking speed on the street. The third act is a video of Ben and Dan each walking along their separate path toward the taco cart. This video shows that Dan did reach the taco cart before Ben.

Taco Cart requires the use of the Pythagorean Theorem to find out who will get to the taco cart first if two people that start at the same point take a different path (each at a different speed). I would use this activity to teach the CCSS-Math 8.G.7 because the paths taken by each of the two people form a right triangle, so students would have to find the length from the starting point to the destination point, the taco cart. The path that the first person takes is the hypotenuse of the right triangle. The path the second person takes is the adjacent and opposite side, so the distance the second person will walk is the adjacent side + the opposite side. In other words, the paths serve as a real-world version of the side length of a right triangle. This activity could be used to teach the CCSS-Math F-IF.4 because the different paths that each of the two people take represent quantities that will be interpreted. Other quantities which are part of this task and need to be solved for are the distance/dimensions (side length of the right triangle) and the speed at which the two people walk (since one walks on sand the entire time and the other on a sidewalk). The distance/dimension and the speed are important factors that will help the student interpret the answer. Lastly, this activity could be used to teach CCSS-Math MP.4 because it models an everyday problem using math. Students will very likely be in a similar situation to that of the problem, which similar factors, and will need the practice in solving this problem. The challenging part of this problem would be for students to calculate how fast each person will take to get to the destination because each person is walking at a different speed, but the teacher can instruct on how to set up this part of the problem so students don’t feel intimidated by it. Other than that, the students will be positively challenged to set up the problem using their knowledge of the Pythagorean Theorem to find side lengths and use their problem solving skills to find the answer and interpret it as well.