It's got a funny sounding name but it sure is a powerful tool to use in the primary classroom!
A Rekenrek (also known as an arithmetic rack) is a tool that was developed to help students subitize numbers (see numbers in groups). Seeing numbers in groups allows students to add and subtract more efficiently rather than counting by ones or counting on.
A Rekenrek is a row of beads that are grouped into 2 groups of 5. Typically one group is white and the other red. See the image below:
I've been using Rekenreks as quick images for subitizing and their mental math ability has grown by leaps. I started learning about Rekenreks when beginning a unit from Contexts for Learning. Their Double Decker Bus unit required the use of Rekenreks for the whole unit and I couldn't wait to begin it! The only problem was that I didn't have any Rekenreks for my students to use.
So, I went on a search online and found a great digital Rekenrek from the Math Learning Center. It made my life so much easier! I was thinking of creating my own using beads and cardboard a la Pinterest. Who has time for that???
I'm lucky that my class has access to a full set of chromebooks as well as some ipads so each student had their own personal digital Rekenrek. I also displayed it using the projector so that the whole class could see when we did quick images or when I wanted to demonstrate a problem (or have a student demonstrate a problem/solution).
What I like about this digital rekenrek is that it also comes as a free app for your tablet. You can also add as many rows as you would like depending on the numbers your students are working with. Just hit the plus symbol and a new row is added.
If you're thinking of trying Rekenreks in your class or you are looking for an additional resource, I created these activities that can be used with your whole class or for small group work. Click here or on the images to learn more about this product.