# CL Newsletter, October 2021 - Favorites From Our Favorites

Through our work here at Desmos and our interactions with the community we often come across things that make our lives easier, our work more efficient, or our lives more delightful. Sometimes these take the form of actual CL tools like pattern matching; other times they’ve been CL-related things like editing multiple lines at the same time (like this!); and in many instances, it’s been activities created by you, fellow activity builders. This month we brought along a few friends—Jenn Vadnais and Martin Smith—to share some of their discoveries.

# Jenn Vadnais—Feedback in Two Forms

Table entries can be displayed in sketch components. This is done by connecting the numeric value of the cells in the table to number sinks in the CL of the sketch component. Now students can quickly determine if adjustment is required.

The sketch component’s annotation tools allow students to demonstrate their mathematical reasoning.

Within the graph, the length and width inputs are calculated and compared to the correct area. This result is then compared to the correct sink criteria inside the table’s CL, and the appropriate feedback is displayed on the teacher dashboard. Check out this activity!

What We Think

The use of the sketch component here to both interpret the student’s numeric response (via graph background) and show their thinking through drawing is brilliant! In many activities we offer students the opportunity to “use the sketch tool if it helps with your thinking”, but we rarely see it used in concert with the graph background as a digital “explain your thinking” field.

# Martin Smith—Toggle Images Using currentX and currentY

Two CL sources that are personal favorites are currentX and currentY. These sources encourage exploration and interaction while giving the student greater control over their learning. This activity uses CL to make images “current.” When the cursor is placed within the boundaries of an image, the image will awaken.

In the graph, the position of point (X,Y) determines which background images will become visible.

The position of point (X,Y) also determines the location of the sparkly stars.

The currentX source overwrites the value of X in the graph with the cursor’s x-location.

The currentY source overwrites the value of Y in the graph with the cursor’s y-location.

The layering of an image is determined by its position in the expression list (images higher on the expression list appear in the background, while images lower in the expression list appear in the foreground).

Line 8 has “eyes shut” as the default background image.

Line 9 has “eyes open” that will conditionally appear in the foreground as the cursor moves over the image (see below).

When the cursor’s x-coordinate is within 3 units of –5 while the cursor’s y-coordinate is within 4.83 units of 5, the “eyes open” image is displayed.

What We Think

currentX and currentY are fantastic tools that allow students to interact with graph displays without the need to click and drag. It’s also great for making diagrams more dynamic (get your non-math colleagues in on this!). Additionally, using it alongside actions can lead to some serious fun!

## One Last Thing

We’d like to thank Jenn and Martin for offering up their thoughts in writing. Be sure to find them online through Twitter (@rilesblue and @mathface22) or in our Facebook group.

We couldn’t end this newsletter without sharing something from the CL team. One thing that was always difficult (and in most cases even impossible) to achieve was the ability to rewind an animation back to the beginning. Thankfully, we finally have a tool that’s quick and easy to use, and will make it possible for you to reset feedback with an animation cover when a student edits their response (or on any other trigger).

resetAnimationOnChange works like every other resetOnChange sink. Identify the change that will trigger the reset (e.g., a math input’s latex or a button’s pressCount), make sure its a string, and assign it to the sink. Stuck? Check out the entry in the Computation Layer documentation.