Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4611307 | Function analyzing | William M. Kahn, David Shapiro | 1986-09-09 |
| 4381554 | Calculator for storing source data and evaluating numerical answers to problems | William M. Kahn, David Shapiro | 1983-04-26 |
| 4309761 | Calculator for evaluating numerical answers to problems | William M. Kahn, David Shapiro | 1982-01-05 |
| 4198684 | Electronic calculator with keyboard-controlled unary function capability | William M. Kahn, David Shapiro | 1980-04-15 |