The previous post listed some suggestions about teaching decimal fraction concepts, including ideas for modeling. On this page a computer software program that will represent decimal numbers is described.

Hi-Flyer Decimals

The program acts much like an electronic box of place-value blocks. Students can click on buttons to show blocks representing decimal numbers, then use various tools to manipulate the representations. By opening certain windows, the number can also be represented by the written symbol, a "numeral expander", and the number name in words. As the block representation is changed by adding or taking away blocks, the contents of each window changes simultaneously.

Screenshot: Hi-Flyer Decimals

The capabilities of this software were demonstrated at the NCTM 1999 Annual Meeting in San Francisco.

If you would like to check out Hi-Flyer Decimals, just visit the store to browse the products available.

Using the Computational Power of Computers

Computer-generated place-value blocks have a number of benefits compared to conventional physical blocks, including:

  • The representations are "cleaner" (Clements & McMillen 1996) - the blocks can be arranged in orderly rows, and so that they are not overlapped;
  • The software can dynamically demonstrate processes such as regrouping;
  • The computer "knows" how many blocks are on-screen, and can use that information to provide accurate data for on-screen windows;
  • The computer can free the student from cognitive processing, allowing consideration of other aspects of the number concepts (Price 2001).


Clements, DH & McMillen, S 1996, ‘Rethinking "Concrete" Manipulatives’, Teaching Children Mathematics, vol. 2, pp. 270-279.

Price, PS 2001, 'The Development of Year 3 Students’ Place-Value Understanding: Representations and Concepts', unpublished doctoral thesis, Queensland University of Technology, Brisbane, Australia.

These notes were prepared as handouts for a conference session:

NCTM 1999 Annual Meeting - San Francisco [Visit the NCTM site]. They were previously hosted at, and were moved to Classroom Professor in April, 2010.