Number Rack

The Number Rack facilitates the natural development of children’s number sense. Rows of moveable, 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 that use iPod Touches, iPhones, or iPads.

Visit our site for more information about using the Number Rack, including a free activity guide:

www.mathlearningcenter.org/apps.

FEATURES:

• Display 1 to 5 rows of beads, 10 beads per row. On the iPad, display up to 10 rows.

• Hide beads with the resizable shade, which allows teachers or learners to model subtraction or difference problems. For example, if there are 20 beads in all and 17 are visible, how many are behind the shade. Or posed as an equation: 17 + ? = 20.

• Use the “start over” button to quickly reset all the beads and begin a new exploration.

LEARN MORE:

To learn about Bridges in Mathematics, an elementary curriculum that employs visual models like the Number Rack, please visit:

www.mathlearningcenter.org/bridges/overview

ACKNOWLEDGEMENTS:

This resource is brought to you by The Math Learning Center, a nonprofit organization dedicated to K-12 education since 1976. The Number Rack app was made possible by a generous donation from Dr. David Moursund.

This app was crafted by Clarity Innovations, a firm that creates solutions that match promising technologies with the needs of education to improve the process of teaching and learning. Learn more about Clarity Innovations on the Web: www.clarity-innovations.com.