Adding a variable to itself

Questions
1

Hi there,

Quick question (and hopefully a quick answer) - is it possible to add a variable to itself in desmos? In other words, can I define a variable then increment it somehow? For context I’d like to count how many times a student gets the answer correct on a randomly generated practice activity and eventually place a point value based on if they needed a hint or not.

Essentially I want something like this:

a= when “correct answer” a+1 otherwise a

I’ve got a good flow on randomly generating lots of different practice through the CL/calculator in activities, and I think this would be the next level to add some additional tracking engagement. I have fun gifs and word prompts that trigger when something is right, but no way to track how many questions a student actually attempted and got right.

2

I’m not certain there’s a way to do that, but there are other ways to accomplish what you want.

How is a new problem generated after one is completed?

Do you want them to be able to move on to a new problem before correctly solving the current one?

3

You’ll want to take advantage of using the capture sink when a student submits a problem. If all the problems are on one screen, you can create a variable in the calculator that checks for correctness. Set the variable to 1 on correct, set it to 0 if not correct. The button will capture those values and then you can use the calculator to perform some functions on the numberList history. Here’s an example.

5 Likes
4

Oooohhhh, Craig’s right. You can effectively increment (if that’s your end goal) by asking for the length of a numberList!

5

ok wow, very cool! I haven’t used any of this functionality before so I think I need to sit down and code out some examples for myself to internalize it-but yes, this is exactly what I’m looking for.