Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6575755 | Fraction circle | — | 2003-06-10 |
| 5820381 | Teaching apparatus and method for visually representing mathematical expressions | — | 1998-10-13 |
| 5645431 | Teaching apparatus and method for visually representing mathematical expressions | — | 1997-07-08 |
| 5433611 | Teaching apparatus and method for visually representing polynomial expressions | — | 1995-07-18 |