“Rekenreks are similar to an abacus,” Ruth Anna wrote in a blog post, “although much more economical… With some cardboard, fish line, large beads, and hot glue, you can create your own stash.”
In this classroom video, Ruth Anna demonstrates how rekenreks enable her class to review math facts and grasp relationships between sets of numbers.
Ruth Anna: Are you ready? So am I.
Ruth Anna: When you get rekenrek, I want you to push all of your beads to the right. And I think for today, when I give you your rekenrek, place it on the floor like this.
Ruth Anna: Everyone have their beads pushed to the right?
Ruth Anna: Alright folks. So today, we’re going to do little bit of review before we talk about another number. I want all of you to show me a way to make eight. Show me one way to make eight.
Ruth Anna: Alright. Maybe you didn’t know this but I chose a way of making eight, as well. We’re going to see if any of you have my way of making eight. Now let’s look real carefully. Does everyone think they have a way of making eight? Double-check to make sure that you’re only showing eight.
Ruth Anna: Alright. Conrad, are you ready? You can tell us your way of making eight.
Conrad: Six plus two.
Ruth Anna: That’s right. What’s your way of making eight, Leah?
Leah: One plus seven.
Ruth Anna: One plus seven. Is that a way of making eight? It is! That’s right! What’s your way, Elena?
Elena: Two plus six.
Ruth Anna: Two plus six. Now, your way is related to Conrad’s way, right?
Ruth Anna: Now, we’re going to do something else. The new number that we are just talking about in math is eleven. What I want you to do, I want you to take your beads, push them all to the right again. Alright. This time, I’m going to let you hold your rekenrek up beside you like this so just you see it.
Ruth Anna: Now, I want you to use both rows in your rekenrek to show me a way of making eleven. What number are going to make?
Ruth Anna: Eleven. When you’re finished, just hold your rekenrek like this so your beads don’t slide back.
Ruth Anna: Alright. So, what is eleven? There are a bunch of ways of making eleven. Let’s see what you came up with. So, Caroline, what did you come up with?
Caroline: Five plus six?
Ruth Anna: Five plus six. Can you show it to the class?
Ruth Anna: Is that a way of making eleven?
Ruth Anna: Yes. You know what I see here with Caroline’s way? I can look at these groups of numbers, I can see five, ten, plus one. And that’s?
Ruth Anna: Eleven. Right. Nice, Caroline. That’s a good way of making eleven.
Ruth Anna: And, Conrad.
Conrad: One plus ten.
Ruth Anna: How did you show that? One plus ten. Do you see Conrad’s? One on the top and ten on the bottom.
Ruth Anna: Nobody has my way of making eleven. Even though you are all right. Can you look what is my way of making eleven?
Ruth Anna: Oh, is this ten?
Group: Nine plus two.
Ruth Anna: That’s right. And the reason that I chose nine plus two is that because this was our new math fact yesterday. Who remembers that? Nine plus two.
Ruth Anna: Let’s say it all together. Ready, and say:
Group: Nine plus two equals eleven.
Ruth Anna: I about couldn’t hear you.
Group: Nine plus two—
Ruth Anna: Hang on. Hands in your lap. Now, can I hear you again? Everyone has your hands in your lap? Alright, and say—ready?
Group: Nine plus two equals eleven.
Ruth Anna: That’s right. Raise your hand if you know the related fact. Okay. How many am I going to put on top?
Ruth Anna: Two. How many on the bottom?
Ruth Anna: That’s right. Two plus nine is also related. Two plus nine is another way of making eleven.
Ruth Anna: Let’s collect the rekenreks and then we’ll do more with our math lesson.
Ruth Anna: Okay, today, Conrad you get to bring those back.
For more on the ways rekenreks can improve your students’ math abilities, see Ruth Anna’s blog post and her previous rekenrek demonstration:
CONTRIBUTOR: Ruth Anna Kuhns