Elementary Math, Math, Math Instruction, Uncategorized

What the Heck is a Rekenrek???

Hi friends! This is Emily, and I am excited to join Kristin on this journey of helping to improve math instruction and share ideas with all of you. For my first post I wanted to share an idea with you that I started doing last year with my class during the first week of school. If you make rekenreks with your class I would love to see pictures and hear what your students think about them. Feel free to post any pictures or comments!

Are you looking for a math activity to do the first week of school with your students? Do you want that activity to show both your students and yourself what you will be working with this year? Have your students each make a Rekenrek! You may be wondering, what is a rekenrek? A rekenrek is a visual model of a number rack. You can have them in your hand to manipulate or you can use an electronic one (https://apps.mathlearningcenter.org/number-rack/). I’ll be 100% honest, the best part for the students is the making of these number racks or reken reks.

I really enjoy cooking, so this next part is going to come off as a recipe. 🙂

Materials Needed:

  • Plastic Canvas (the hard plastic waffle board for crafting)
  • Black Fuzzy Sticks (pipe cleaners)
  • Pony Beads (white and red)
  • The amount of materials depends on two things:
    • Number of racks on your rekenrek
    • Number of students
  • Cut the plastic waffle board with sharp scissors about
    • 6 square inches if doing the 10 racks rekenrek (3rd – 5th)
    • 2 in x 6 in if doing the 2 rack rekenrek (K – 2nd)

To make:

  1. Place a tray or paper plate on each table with the following materials:
  • Black fuzzy sticks
  • Red and White Pony Beads
  • Waffle boards
  • I always put more than they need on those plates


2. Instruct the students to get however many fuzzy sticks they will need.

  • 1 rack for kindergarten
  • 2 racks for first and second grades
  • 10 racks for third, fourth, and fifth grades

3. The students then need to put 5 white beads and 5 red beads on each of the fuzzy sticks. This step will take a bit of time, but is great for fine motor skills.

kids rekenreks 2

4. You’ll have to model this step. The kids will now place one end of the fuzzy sticks with beads on it through the designated hole in the waffle board. (I have the fuzzy stick go through the 3rd hold on each side of the waffle board.) Have them put the other end of the beaded fuzzy stick on the other side of the waffle board and pull tight, but not bending the waffle board. On the back, the fuzzy sticks will be twisted together.

5. For the next rack on the rekenrek, leave two boxes on the waffle board and stick the end of the next fuzzy stick through the 3rd hole from the side. Then, have the students put the other end of the beaded fuzzy stick on the other side of the waffle board and pull tight, but not bending the waffle board. On the back, the fuzzy sticks will be twisted together.

6. Continue these steps until all of the racks are placed on the waffle board and your rekenrek is complete.

After the number racks or rekenreks were constructed, I asked the students to explore with them for a few minutes. I walked around the room and listened to what my students were saying. I heard things such as “What is this thing?”, “How does this thing work?”. While others were saying things like, “I have 100 beads, you both have 100 beads, we have 300 beads in all at our table.”  Or things like, “I wonder how many fuzzy sticks Mrs. Kappel had to buy for all of this!” My plan was to just have the students make and explore on this day, but their questions and comments led to our greatest unplanned math talk of the entire year… yes it was day 2 of the school year.


After about 5 minutes of exploration, I started asking the following questions. I gave them think time, then share time at their tables, then we shared as a class. I was setting them up for how the sharing would work for our school year and reminded them over and over that mistakes are ok and we will learn from them. Sometimes a wrong turn, leads us to the right turn.


Sample questions to ask:

– How many fuzzy sticks do we have in the classroom in all?

  • The goal is for them to count by 10s. If they multiply the number of students in the class by 10, that’s a huge plus!

– How many beads do we have in all for our class?

  • The hope is my 4th graders to count by 100’s.

– How many red beads are on our number racks?

– How many white beads are on our number racks?

  • Each time, I’m asking… How do you know that?
  • I let my students know on day 2, I’m more concerned with their thinking than the final answer they give me.

– The hundred packs of the fuzzy sticks were sold out at Wal-Mart when I went to buy them, so I had to buy in packs of 25. How many packs did I need to buy?

  • This is a hard question, but I loved hearing how they came about finding their answers. My class had exactly 25 students in it last year, so I was thrilled with all the answers they came up with. Some I hadn’t even thought of and I made sure to let them know that.

– If each 25-pack of fuzzy sticks cost $0.88, about how much did I spend on fuzzy sticks?

– How many packs of red pony beads did I need to buy to make sure everyone in the class had 50 if I buy them in packs of 500 ?

– So how many packs of white pony beads did I need to buy?

  • How do you know that?
  • Hoping they say we needed the same amount of white pony beads as we did red.

– If the pony bead pack contains 500 beads, how many packs do I need to buy?

– About how much would I spend on pony beads for our class if each bag of 500 pony beads is $1.97?

  • How do you know that?

We then moved on to how the number rack worked.

I pulled up the online number rack at https://apps.mathlearningcenter.org/number-rack/ on my Smartboard and had students demonstrate on the board while all students modeled at their seats.

– Show me 6.

– Show me 25.

– Show me 32. Now show me 13 more.

– Show me 76. Now take away 4. Take away 4 more.

These are some basics that got them understanding how the number racks work.

There are tons and tons of activities out online for rekenreks and number racks. The following links are some that have been recommended to me by my friends in the math world.

  • Shannon Samulski, the owner and operator of sis4teachers.org, has written a few blog posts about rekenreks/number racks this summer. They offer some amazing descriptions, advice, and activities. Her blog link is here… https://sis4teachers.org/blog/… Go here and then find the two blogs from this summer called Abacus Fun: Part One, Abacus Fun: Part Two, and What the heck is a Rekenrek? Great resources!
  • Another great resource for rekenreks or number racks is https://bridges1.mathlearningcenter.org/files/media/Rekenrek_0308.pdf. This PDF was what I first used when I was initially exposed with this amazing modeling tool.
  • K-5 Math Teaching Resources appears to be a good resource for math activities. This particular page regarding rekenrek’s has great ideas on how to incorporate the Concrete-Pictorial-Abstract ideas into the classroom. Check out the reading and pictures on this page. https://www.k-5mathteachingresources.com/Rekenrek.html

I would love to hear other ideas you come up with for using your rekenreks! Have fun with these, and most importantly, have fun exploring math concepts this year with your students.



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