Rekenrek – a great K-2 manipulative


A rekenrek is one of my favorite early elementary math manipulatives. First designed by Adrien Treffers from the Freudenthal Institute in Holland, a rekenrek is a set of 20 beads organized into two rows of 10, with 5 red and 5 white beads on each row. You can easily create and recognize each number from 1 – 20 using the groups of 5 beads. For example, if I push the whole first row to the left and 2 beads on the bottom row, I can quickly recognize the number 12.


The ability to “see” numbers rather than counting them is called subitizing and is an important early indicator of number sense. Normally we are only able to subitize small numbers (1-4), but the rekenrek helps children quickly see larger numbers as combinations of sets. For example, I can quickly see that there are 8 beads if I see 5 red beads and 3 white. I could also show this with linker cubes, but it takes a lot longer to count out and construct stacks of linker cubes.

The rekenrek is also quick way to demonstrate and practice addition strategies. You can demonstrate counting on with the problem 6 + 3 by first sliding over 6 beads as a group, saying “6,” and then sliding over three more beads individually, “7, 8, 9.” Remember to say “7, 8, 9” rather than “1, 2, 3” as you are sliding over the beads because you want students to still be able to count on even when they don’t have the beads in front of them.

rekenrek-4You can practice near doubles (or doubles plus one) by first creating a doubles problem such as 4 + 4, by sliding over 4 beads in each row. Then slide over one more bead on the top row to create 5 + 4 or one more bead on the bottom to create 4 + 5.
rekenrek-2Demonstrating near tens is easy on the rekenrek. Let’s say you’re trying to solve the problem 8 + 4, first slide over 8 on the top row. Then slide over 2 on the top to complete the 10 and 2 more on the bottom to make 12.

Here are a few extra resources: rekenrek activites and instructions for making a class set*.

*I made my class set of rekenreks with pipe cleaners instead of string because that way my kids could help. Watch the video below for tips on making a class set.

Celebrating Digital Learning Day

As we celebrate Digital Learning Day today (, #DLDay), I’d like to take a few moments to reflect on the on-going debate over the use of technology with young children and share some ways Teachley is integrating physical and digital learning. Here are just three of the many complex reasons people hesitate to use technology with young children.

1) Because adults themselves don’t know how to use it. I’ve often heard “If I’m an adult and don’t understand something, a 7-year-old isn’t going to.” But, young kids surprise us all the time with the things they know. They are naturally inquisitive, exploring and figuring things out all on their own. Last week I got a video from my almost 7-year-old niece. She recorded the video on her new iPad, saved it, and uploaded it to me without ever having been told how. In fact, she taught her parents how to do it. Successfully integrating technology in education requires us to leave our comfort zone to try new things, risk failure, and learn alongside children.

2) Because it’s not the way we picture early childhood. Traditionally, early childhood has been a time to play, explore one’s world, build relationships with others, and develop social/emotional skills. Academic competencies have played a minor role in early childhood education, and the use of technology has been almost non-existent. But, the debate doesn’t have to be play or technology. There are wonderful educational apps and digital books available today for young children. No one (at least I hope not) is suggesting we replace all physical books or blocks with digital ones. The debate should instead be about finding the most effective tools to enhance learning and the right balance between the physical and virtual tools, which leads me to the third reason.

3) Because there is no evidence that it works. Research on the early use of technology date back at least 40 years (remember Logo?), much of which demonstrates the benefits of these tools. We do, however, need more. There has been such a rush to develop “educational” software and apps that we haven’t had time to test it all. That’s why it’s important to understand who is developing software and what role research has played during the development process. Is it based on what we know about how kids learn? Does research show that it’s an effective learning tool? How rigorous was the research?

At Teachley, we value the integration between physical and digital learning. To help enhance the content taught within our digital games, we create classroom activities using physical materials and manipulatives that teachers can incorporate as part of their regular lesson plans. For example, our first app, Addimal Adventure, teaches different strategies for learning addition. Children are able to flexibly choose amongst the strategies while solving addition problems. To help reinforce the Count On strategy taught in the app, we created a classroom Count On lesson using unifix cubes. 

digital-learning-addimalsIn honor of Digital Learning Day, we’re giving away Addimal Adventure and our Count On Lesson for FREE.  

To download Addimal Adventure, go to:

To download a free copy of Teachley’s Count On Lesson, go to:
For more lessons, join our Pilot Classroom Learning Analytics Program. As a participant, you receive classroom performance reports that identify your students’ progress on the Addimal Adventure app, benchmarks met, skills students are struggling with and more. We also identify which lessons students are ready for and provide you with sample lesson plans.  To join, complete the registration form at

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