standard_description: Apply properties of operations as strategies to add and subtract. (Students need not use formal terms for these properties.) Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)
problem_activity: Anton writes a model that describes the number of tacos his friends eat as a function of the cost of the total tacos. Below is a graph of the model.
[IMG]
Anton writes a second model that describes the total cost of the tacos as a function of the number of tacos his friends eat. Below is a graph of the model.
[IMG]
Label the axes appropriately. Which one makes more sense?
How are these two graphs similar? Different?
How are these two equations similar? Different?


aligns: no