Addition to 10 with the rekenrek

General

Students learn to add to ten by doing their problems on the rekenrek.

Relevance

It is useful to do your addition problems on the rekenrek, so you can see how many you already have, and how many more you are adding. If you learn to do this well, you can learn to add in your head.

Introduction

Students start by practicing counting amounts to 10. They count all the objects that are on the image on the interactive whiteboard and note the answers. Discuss how many of each there are and fill in the answers.

Development

Make sure that each student has a rekenrek so they can practice along with your explanation. Show them how to recognize the organization in 5s on the rekenrek. Make sure that you always have 5 red beads and 5 white beads on the top row and the bottom row. Practice recognizing amounts. Show the rekenrek on the interactive whiteboard and say that you must count the beads on the left hand side. Point to the left hand side and discuss that you always start with the beginning. Check the answers together and show students the rekenrek with 5 red beads. You can see at once, using the color and the position, that there are 5 beads, so you don't need to count the beads individually. That means you can count quickly from 5. Practice with this and ask students to note their answers. Tell students that you can also use the rekenrek to solve addition problems, by moving the beads together. The beads on the left hand side represent the first number in the addition problem. The second number, you count out in beads and also move to the left. Then you count the total number of beads. How many are there? That is the sum of the addition problem. Practice this a few times with different examples and have students practice on their own rekenreks. Students practice adding on the rekenrek and note their answers. Discuss their answers as a class and show how they work using the interactive whiteboard.

Check that students understand addition to 10 using the rekenrek by asking the following questions:
- How can you quickly see how many beads you have?
- How many beads are on the top row? and the bottom row? What is the total?
- Which side do you move the beads to when you add them together?
- Where are the beads that make up the first number in your addition problem?

Guided practice

Students practice adding to 10 by working out the problems on the rekenrek.

Closing

Have students practice addition on the rekenrek to 10 in pairs. Every pair gets a rekenrek. The first student comes up with an addition problem, and says it out loud. The second must calculate using the rekenrek. They take turns. Say that you must make sure to leave some room between the beads that represent the first number in the addition problem and the second number in the addition problem so you can clearly see the difference. Afterwards, practice together as a class on a class rekenrek by doing a few problems. Students must explain the steps of the calculation. Remind students that they can use the placement of beads, or the colors of beads to quickly recognize amounts.

Teaching tips

Students who have difficulty adding to 10 can practice along with you on their rekenrek during the explanation. Take some time to help students recognize amounts to 10 on the rekenrek. Then let theme see simple addition problems on the rekenrek which only involve one bead moving to the left. Examples like 2+1 and 3+1, 4+1, etc. Students who are comfortable with this goal can be challenged to solve the addition problems without the rekenrek.