Classrooms can be powerful places where students are exposed to each other’s thinking, from sharing ideas to exploring new approaches and solutions. When math is social, it helps us learn in ways we can’t when we’re alone. This month, we’re going to explore one feature of the Activity Builder that makes these kinds of experiences possible. Behold, *aggregate*.

If you’ve ever used any of our Classroom Data Collection Screens, you may have noticed that we have the ability to immediately display responses from all students without having to open up the teacher dashboard and project the graph overlay. This is the aggregate function at work.

**So what exactly is aggregate?**

It’s a function that retrieves the numeric response of *all the students* in an activity. We’re able to retrieve *any* numeric value students enter or interact with on their screen, from values entered in a table or a math input to the coordinates of points placed on a graph.

Suppose you want students to estimate the position of a number on a number line and then you want them to see where everyone else placed their point. For this type of interaction, we can split it over two screens. On Screen 1, students move their own point. On Screen 2, we retrieve the movable point values of all students.

In our example, we named the x-value of the individual student’s movable point “a”. We’re able to graph their point and the points of the entire class:

**number** **(** `a`

**)** **:** **graph1.number** **(** `a`

**)**

**numberList** **(** `a_{class}`

**)** **:** **aggregate** **(** **graph1.number** **(** `a`

**))**

That’s it! Those two lines are all you need to send a student’s data and their classmate’s data into a graph. Now, here are some things you can do with that data:

**Use a different color or opacity.**Using a lighter color or opacity can be an effective way to include several more points without overpowering the screen. Points that have an opacity less than 1 can indicate where there are many overlapping points, which can be helpful in highlighting trends or common responses.

**Try out animations.**A “Show class data” button is a great way to fade in aggregated points, either one by one or all at once. Check out our example below.

**Hide incomplete responses.**When students have yet to respond, aggregated data can be misleading. Suppose you want students to move a point from the origin. Where will the most popular location be? The origin of course! That is unless you only graph responses that are actually complete. Pro tip: A “Submit” button can be great for distinguishing this.