Rekenrek by mathies

The Rekenrek tool helps to build a deeper understanding of number concepts and relationships. 

Mathematical Concepts:

Make visual models that help explore mathematical thinking related to:
•understanding number relationships using anchors of 5 and 10
•representing numbers in different ways, composing and decomposing numbers
•subitizing (instantly seeing “how many”)
•counting principles
•understanding addition and subtraction
•developing multiplicative thinking
•visualizing division facts
 
Features:

•Adjust the number of rows.
•Choose a background colour and bead colours.
•Drag the rods to compare values.
•Hide beads with one of the two resizable shades. Shades can be repositioned to  focus attention.
•Communicate your thinking or highlight various features of your representation using the “pencil” button.