Technical notes




   Terms of Use

   Citing content


   The Future

   My Opinion
Current Site Statistics:
Between May 20 and June 19th had 1608 different visitors visiting the site. 312 (12.46%) were from the United States. 87 signed on several times. is very honored. Thank you. (June 30.2015)

Site Statistics: While rarely takes time to look at statistics, as we have no funding agency to report to, it is occasionally done to help direct the development of these materials. For the month of April, Google Analytics tells us that we had 263 users signing in ( 67 were in the United States and 196 in 25 other countries ). About 7 percent are returning users. is very honored to serve the global community; and hopes that the universal language of Mathematics will spread and become the second language of every learning community on this earth. Thank you. (April 25, 2015)
Clarification of some of the information provided by Google Analytics also shows that a number of users used browsers that translated the information in into local languages. One of the design considerations in developing was to facilitate translation efforts, by keeping the verbiage used to a minimum. Please let know how successful these efforts were: k-12math(at)sbcglobal(dot)net Thank you (May 7, 2015)

Checking Links: While greatly appreciates comments from users on link problems (send to: k-12math(at)sbcglobal(dot)net ), there is an ongoing program to check for link problems. Beyond the random checking that is done frequently, some great time saving link checking utilities are used. Fortunately textbook publishers realize the need for stability.

All the pages you see are written in pure HTML code (efforts are being made to remove the CSS link); except one which is written in PHP code using a small MySQL table. The single PHP program is responsible for the 1000 screens of information that are given in options 2 to 8 on the left side of the Information screen. The writing and updating of 1000 HTML programs to equal what that one program yields would be a nightmare (unless you have half a dozen graduate students in need of ..). The PHP program insures a higher degree of accuracy in reporting the information.

Unfortunately the PHP program has one draw back. When linked to from outside the screen displaces an empty spreadsheet. DO NOT EXTERNALLY LINK TO THE SPREADSHEET ( ). The screens previous to the spreadsheet (options 2 to 8 on the left side of the Information screen) send parameters to the PHP spreadsheet program which then constructs the spreadsheet with content information in it. Doing a screen print is the best way to have a complete spreadsheet. ( assumes the user knows that coping the spreadsheet to an Excel spreadsheet will carry the URLs with it.)

The use of HTML and PHP minimize the problems of adapting to different web operating systems. It has been successful on all major browsers.

Hint: Sometimes it is faster to use your web browser's backup arrow to return to the previous page.

Please let me know if you encounter any problems. Jim Kelly at: k-12math(at)sbcglobal(dot)net

©1972 (paper), 1985 (APPLE II/PC), 2005(www), 2015 Jim Kelly - All Rights Reserved.