Rekenreks are also known as an Arithmetic Rack. They are a great tool that allows children to develop number sense at their own pace. With the built-in 5 & 10 structure, they help children build number relationships that lead to more advanced strategies.
How Do You Use A Rekenrek?
Show the students a sample rekenrek and ask them what they notice. Elicit the ideas that there are two rows of 10 beads and that the color of the beads change at 5.
Show Me (one row only): have students show you a certain number on the rekenrek – “Show me 7 on the rekenrek.” Then ask questions about how they knew where 7 beads was, what they notice about how far it is from 10, from 5, etc.
Show Me (using both rows): just like above, but ask students to show 7 using both rows. This is a nice way to bring up the “math facts” for 7. Some kids will have 5 on top and 2 on the bottom; some may have 1 on top with 6 on the bottom,etc. Use a context like “There are 8 girls on Kylie’s bunk bed; some are on the top bunk and some are on the bottom bunk. Use your rekenrek to show me how many might be on the top and how many might be on the bottom.”
Quick Images: Give them a story like “Kylie is having a slumber party, during the party some of the girls were playing on her bunk bed. I’m going to flash my rekenrek for 5 seconds to show you how many girls were on the bunk bed. I’d like you to show it on your rekenrek and figure out how many girls were on the bunk bed.” (Flash 9 all on top; 7 all on top; 6 all on top; 5 on top, 3 on the bottom, etc.) (Other contexts can be using the rekenrek as a double-decker bus or as the upstairs and downstairs of a house)
How To Make Your Own Rekenrek
You will need:
- Plastic mesh sheets
- Pipe cleaners
- Beads (preferably red and white to match the real Rekenrek)
- Cut the large plastic mesh sheets into rectangle sizes big enough for 2 rows of pipe cleaners and space around the pipe cleaners for students to hold and manipulate the pipe cleaners. (We usually get about 12-15 Rekenrek rectangles from one large plastic mesh sheet).
- Place five white and five red beads on each pipe cleaner.
- Place one end of the pipe cleaner into the holes at one end of the board. Tie the pipe cleaner in a knot on the back so that the children cannot get the pipe cleaners off.
- Thread the pipe cleaners through the holes on the other end of the board and tie a knot on the back.
TA-DA! You just made a Rekenrek!
When looking at the finished rekenrek, the beads should be pushed over to the right-hand side (this is called the “start position”).
- The start position has the beads on the right so that when children push beads over they are “reading” the rekenrek from left to right. They count the beads from left to right just like numbers appear on a number path/number line.
Check out these great resources that are filled with activities and lessons for using the rekenrek!
- How to build a rekenrek and rekenrek activities
- Rekenrek recording papers
- Rekenrek prompts
- Using the rekenrek as a visual model for strategic reasoning in mathematics
- Learning to think mathematically with the rekenrek