Wow! What a big and open topic. I look at the examples given at Illustrative Mathematics

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and it was not what I would have

come up with.

Katy is told that the cost of producing x DVDs is given by C(x)=1.25x+2500. She is then asked to find an equation for C(x)x,  the average cost per DVD of producing x DVDs.

She begins her work:

and finishes by simplifying both sides to get:


Is Katy's answer correct? Explain.

Dig Deeper

So I dig deeper into the meaning and I reread. I see how their example fits the standard, but I want to be able to see this and create it myself.

I believe that all most teachers are in this same boat. We are immobilized by the unknown. For so long we have understood exactly what our kiddos need to do well. We know what the tests look like. We understand the standards. And now.... There is too much unknown. It is overwhelming.

Breaking it Down

And so I begin breaking everything down. By Unit, by week, by standard, by assessment question.It gives me order and control and I feel a bit better. But I want to be careful not to forget the big picture of the Mathematical Practices. That is why I added them to my main unit pages. It is an instant reminder of the bigger picture.

I do not want to fall back into task teaching, although kids need to understand tasks. More importantly, I want to teach kids how to think, analyze and problem solve for their lives, not just in my class. If we can remember the big picture and focus on our big goals for our kids and apply it to Interpreting Functions we can achieve success for ourselves and most importantly our students. So lets jump in....

Interpreting Functions


Understand the concept of a function and use function notation.


1. Understand that a function from one set (called the domain) to another set (called the range) assigns to each element of the domain exactly one element of the range. If f is a function and x is an element of its domain, then f(x) denotes the output of f corresponding to the input x. The graph of f is the graph of the equation y = f(x).