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Fractions - Exploring Part/Whole Relationships
Integers - Representing, Comparing & Ordering
Linear Growing Patterns - Representing
Trigonometric Functions - Graphing Sine (degrees)
Click to open Rekenrek Tool in new window.
MAKE ME SOME SPACE VIA A TRICK FROM GREG
| Rekenrek Tool
Features of the Tool
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.
of your work to share with your teacher or add to a portfolio.
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.
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.
Use the shade to think about 15 + ? = 20.
Click on the + sign to increase the number of rows of beads.
This represents 4 rows of 7 or 4 x 7.
There are 28 beads in total, so we know that 4 x 7 = 28.
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.
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:
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)
Press the pencil icon at the top of the screen to enter annotation mode.
Make notes to explain your thinking.
Features of the Tool
Add a Row
Add one or two shades to the stage.
Shades can be used to hide part of the representation.
Make notes or highlight various features of your representation.
Insert Image Button
You can insert images into the tool (as of version 1.1.1).
Delete all your work and return the tool to its starting state.
Access a link to this wiki, a How-to video, a feedback form as well as copyright details and version number.
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.
Rekenrek Tip Sheet
(Source: EduGAINS /Ministry Developed Resources/ Mathematics / Classroom Practices/Technology and Teaching Tools/Manipulative Use)
What are Rekenreks?
How do Rekenreks help students?
What's New With CLIPS? There's an App for that! OAME Gazette article, March 2014
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
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