Number Rack, by MLC

Number Rack facilitates the natural development of children’s number sense. The movable, colored beads encourage learners to think in groups of fives and tens, helping them to explore and discover a variety of addition and subtraction strategies. This virtual version of the manipulative is an open-ended educational tool, ideal for elementary classrooms and other learning environments.
FEATURES
• Display 1 to 10 rows of beads, 10 beads per row.
• Hide beads with resizable covers, which allows teachers or learners to model subtraction or difference problems.
• Reverse the colors of rows 6 to 10 to distinguish (or not) groupings of 25 beads.
• Use the drawing tools to annotate work and show understanding.
• Add equations, expressions, and descriptions with the math text and writing tools.
• Share work by saving an image or providing a share code to others. Great for creating the initial setup of an activity, then sharing it with students so they can explore it further.