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Rekenrek

Rekenrek
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Contents


This information has been updated for version 1.3.0, released November 2017.

Examples
Features of the Tool
PDFSupports
How-To Videos


Rekenreks are arithmetic racks used to build understanding of whole numbers, number relationships and reasoning for various operations.
Each rod has ten beads, five of one colour followed by five of another colour.

Take a screenshot of your work to share with your teacher or add to a portfolio.

You can access a wide variety of Annotation tools using the Pencil Buttonbutton to communicate your thinking.

You can insert pictures into theTool using theInsert Image Button button.

Examples

Representation of seven

Representing


Represent numbers by sliding the beads to the left.

This shows the number 7.

Five red beads followed by two white beads helps us to see that 7 is equal to 5 + 2.
Representations of 7 as 5 plus 2

Connecting Representations


Create alternate representations using the newest annotation objects (November 2017).

Colour can be used to make connections between representations.
Representation of seven plus eight

Addition and Subtraction


Slide 8 beads to the left on the second row.

This now shows 7 + 8 = 15.

Alternatively, ten red beads and five white beads help us to see that 15 is equal to 10 +5.

Or, if we think about the white beads on the right hand side, we can think of 15 as equal to 20 - 5.
Representation of 15 plus a hidden quantity is 20
Use the shade to think about 15 + ? = 20.
Plus icon
Click on the + sign to increase the number of rows of beads.
Four rows of seven

Multiplication


This represents 4 rows of 7 or 4 x 7.

There are 28 beads in total, so we know that 4 x 7 = 28.
Four groups of 5 plus four groups of 2
If we look only at the red beads, we see 4 groups of 5.

The white beads show 4 groups of 2.

So, the colours help us to see that 4 x 7 = 4 x 5 + 4 x 2.
Representation of the cookie problem

Image Import

It might be helpful to import a screencast of the question you are working on.

The rekenrek provides a powerful visual representation that could be used to support a variety of multiplication strategies.

How might you use this representation to support reasoning related to:
  • counting
  • halving then doubling (8 x 9 is 4 x 9 doubled)
  • decomposing 9 (8 x 9 is 8 x 5 plus 8 x 4)
  • using an anchor of 10 (8 x 9 is 8 x 10 minus 8 x 1)
  • another approach?
Annotations of representation that one-half of 100 is 50

Annotation Mode


Press the pencil icon at the top of the screen to enter annotation mode.

Make notes to explain your thinking.
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Features of the Tool

Plus Button

Add a Row

Shade Button

Show Shade

Add one or two shades to the stage.
Shades can be used to hide part of the representation.
Pencil Button

Annotation Tool

Hide/Show a wide variety of Annotation Tools which can be used to communicate your thinking.
Insert Image Button

Insert Image Button

You can insert images into the tool. More details.
Reset Button

Reset

Delete all your work and return the tool to its starting state.
Information Button

Information

Access a link to this support page, a How-to video, a feedback form as well as copyright details and version number.
Settings Button

Settings

Use this mode to adjust the bead and background colours as well as hide, delete or move rows.
The tool is also completely functional in this mode.
Tool in Settings Mode
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PDF Supports

mathies Rekenrek Learning Tool Tip Sheet

Rekenrek Tip Sheet
(Source: EduGAINS /Ministry Developed Resources/ Mathematics / Classroom Practices/Technology and Teaching Tools/Manipulative Use)

Visit EDUGAINS for additional Tip Sheets.


What's New With CLIPS? There's an App for that! OAME Gazette article, March 2014

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How - To Videos

Videos are provided in two formats to allow for use on a greater variety of browsers and devices.
Exploring the Basic Functionality

Video Transcript
Not working? Try mp4 format

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