Learning about Domain and Range

Domain and Range Matching Activity

If you're coming here from my Domain and Range Intervention post, the blue graph cards helped a whole lot! In this post are more ideas for teaching the topic and what has worked in my class (after we get over the initial hump!) 

When first introducing the topic of domain and range, I always get a lot of blank stares. I get a lot of x values for range and y values for domain. I get a lot of domain intervals heading from infinity to negative infinity. Each year, I add more and more to this unit, filling in the gaps from the year before, and this year is already shaping up to be no different. This week I decided to add a quick [hand-drawn] sorting activity to solidify domain.

domain sorting activity

The activity was super quick for some students but took 15 minutes for others. Please excuse the hand-drawn graphs. I'm a little ashamed! You can also make fancier graphs in Graph Free.

absolute value

Every year, I love listening to my students to see where their misconceptions are. More often than not, their misconceptions are completely fascinating. One girl became very confused that, in the above graph, the domain went to positive infinity but the range came from negative infinity! And I see her point! I mean, the arrows are pointing down, after all. This lead to a great discussion about the right arrow pointing down AND right. Her confusion reminded me of a poster I had squirreled away on my computer:

I really like matching activities, especially for tough topics like domain and range. Because there is a finite set of answers, students can confidently complete matching activities pretty early into a unit. These activities also help students make connections on their own that they can then use later during more open-ended work. About half-way through our unit, I give students this longer domain and range matching activity

Domain and Range Matching Activity

After matching all of the domain and range slips onto their cards, my students sort their cards into 2 piles - function or not a function. This acts as a good review of our previous unit on functions. It's fun watching them work together to figure it all out.

Domain and Range Scavenger Hunt

I don't like giving quizzes, which I know is controversial! My students are super anxious from years of failure and I just don't feel right about perpetuating it. When I do give quizzes, they are always open-notebook. For many students, Algebra 2 is their last public school math class. I want my students to leave high school with a good feeling about math so that they are more likely to go on to take more courses. Instead of a quiz, we complete a domain and range scavenger hunt to sum up understanding. 

If you are looking for a few different activities to cover domain and range, this discounted domain and range bundle has three different activities to differentiate or to offer choice.

Domain and Range activities bundle

To keep up their skills so that all this hard work doesn't get lost, we've been using this quick check template for warm ups, quick checks for understanding and exit tickets. I print a stack and am good to go for weeks. Each day, I give my students either a graph or an equation and they fill in the rest. You can read more about how we use this template in the post Quickly Checkin' Algebra 2.


  1. Do you have a bundle that includes all pendants that have been created?

    1. I do. It's called "Math Pennants Growing Bundle" and can be seen here: https://www.teacherspayteachers.com/Store/Scaffolded-Math-And-Science