# Help turning student estimates in to coordinates

I want students to look at a picture and make an estimate (slide 1). Then on slide 2, I’d love for the student estimate to be plotted on the x-axis with the coordinates (estimate, 0). Ideally, their estimate would be one color and all the other student responses in the class will be in another color.

Here’s an example: Estimation: Playing with CL • Activity Builder by Desmos

I’ve been trying to wrap my head around how to do this using the Desmos CL documentation, but I can’t seem to make headway and getting discouraged by my lack of progress. And wondering if what I’m trying to create is even possible.

Anyone have ideas? Feel free to modify the activity above.
Cheers!
Chase

Hey Chase,

Here’s an example of what you’re trying to do:

On screen 2, I added an ordered pair `(a,0)` into the graph. I then added a script:

``````number("a"): est.numericValue
``````

Now, when the student types in a value, it gets populated into the graph as `a`, which makes the point appear. Before the student types in a value, `a` is still populated (as `NaN` or not-a-number), but that causes the calculator to not graph the point that depends on it, since we don’t know where it would go.

For the second part of your question (how to make all the other student’s estimates appear):

``````numberList("L"): aggregate(est.numericValue)
``````

Here I used the `aggregate` function. This function evaluates the expression provided for every student in the class, and gives you a list of these values (in this case, `est.numericValue`, which is just the estimate each student wrote on screen 1).

I then insert that list into the graph with the `numberList` function, and there it is similarly plotted by the `(L, 0)` expression. You can change the visual appearance of these points by click-and-hold-ing on the circle to the left of the expression.

Another important thing to note is the order of the expressions. Because `(a,0)` is second, it will be drawn on top. Otherwise, that point would be covered up by the list - since the student’s own estimate is included in the aggregated list from the class.

1 Like

Thank you for such a prompt reply! Seems like I was close, but needed to have (a, 0) in the commands for the graphs? Thanks for showing me how to also graph all the student responses as well.

Will the student’s answer be a different color and easily recognizable on the second slide from the class data?

I updated the activity and the text above with some more clarification about styles.

Unfortunately, it’s a bit awkward to test “aggregate” functionality right now. Our best way of doing so is to save the activity, create a class code, then try joining it as several students (using incognito mode can be helpful here).

Here’s how this activity looks like when some students have added their estimates:
https://student.desmos.com/?prepopulateCode=pk5r4m

Bueno!!! I’m working with 12 teachers this afternoon…I’ll make them my guinea pigs!
co