What is a Rekenrek?

• Meet the Rekenrek: Begin by asking children what they notice about the rekenrek. Then introduce the ‘start position’(all beads over to the far right) and have them practice sliding beads in groups rather than one by one “Put your beads in start position. Now, without touching your rekenrek, count the first three beads in your mind. On the count of three, slide all three beads at once across the string. One… two…three!” Repeat with other numbers.
  
  
• Show me 0-10: Say a number, or hold up a numeral card (0-10). Ask students to show the given number on their rekenrek by moving the beads with one push.
  
  
• Show me 11-20: As above but ask students to show the given number of beads using only two pushes.
  
  
• Quick Images: Push some beads across and display them briefly before covering them with a piece of cloth or card. Ask, “How many beads did you see? How do you know?” Asking children to draw or write what they saw on a dry erase board ensures that everyone is actively involved and serves as a quick assessment. If using a 100 bead rekenrek gradually add rows until you are displaying quick images to 100. This can be extended by asking students to show the number that is one more/one less/ten more/ten less than/double the number flashed.
  
  
• Finding Different Ways to Make a Given Number: Initially use only the top row of beads. Cover the bottom row with a folded sheet of card or piece of fabric. Begin by sliding the red beads to the left and the white beads to the right on the top row of the rekenrek. Choose a number to build. “Let’s see how many ways we can build 6 by sliding beads from each side to the middle. What if I slide 4 red beads from the left and 2 white beads from the right. Does that make 6 beads? Can you think of another way to make 6? Record the different ways 6 can be built.This activity should be repeated many times using different numbers from 1-10. Once children are confident using the top row, combinations can be found using both the top and bottom rows. Children can record the different ways they find to build the given number.
  
  
• Building Missing Addends: Ask a student to be your partner. Tell the class that you and your partner are going to build the number 6 as a team. You will move beads on the top row of the rekenrek and your partner will move beads on the bottom row. “I am going to slide 4 beads to the left on the top row. Now in one move, you slide beads on the bottom row to build the number 6.” Pair students up and have them choose a number from the number cards. They then work with their partner to build that number. Begin with cards 1-10, later increase to 1-20. When using number cards 11-20 help students see that certain combinations require a minimal number of beads on the top row to build numbers larger than 10.The ten row rekenrek can be used with students who are ready to represent numbers larger than 20. Have students work in pairs, taking turns drawing a 1-100 number card and building the numbers together.
  
  

• Show 5: How many different ways can you show 5 on your Rekenrek? (repeat with different numbers)
  
  
• Doubles: How many different doubles facts can you show on your Rekenrek? Record.
  
  The above two work samples were completed by a Kindergarten student. This student represented her work on the Rekenrek very clearly on the blank pages in her Math Journal using pictures, numbers and words. To begin with some Kindergarten students may find it difficult to represent their work on the Rekenrek on paper. Having Rekenrek paper available for children who choose to use it is one way to scaffold early attempts at recording. You may like to leave a supply of this paper in your Math Center to prompt children's recording during Math Center sessions.
  
  

Rekenrek Recording Paper

• Near Doubles: How many different ‘near doubles’ can you show on your Rekenrek? Record.
  
  
• Turn Around Facts: Show an addition fact on your Rekenrek. What would the turn around fact look like? Repeat.
  
  
• Number Stories: Have children use individual arithmetic racks as a tool to solve various types of addition and subtraction number stories. This may be used as a journal or oral activity, with the focus on children explaining their strategy for solving the problem.Be sure to include open-ended problems that have more than one solution which can be modeled on the rekenrek, such as the following:
  
  
• There were 8 children on a bunk bed. Some were on the top bunk and some were on the bottom bunk. How many children were on the top bunk? How many children were on the bottom bunk? Show as many different solutions as you can.
  
  
• There were 12 passengers on a double-decker bus. Some passengers were on the top deck and some were on the bottom deck. How many passengers were on the top deck? How many passengers were on the bottom deck? Show as many different solutions as you can.