1. Recreational Math- Mathemagics J. Sriskandarajah AMATYC Conference Las Vegas, November 13, 2009

2. 1776 and Abraham Lincoln (02-12-1809) 1776 is not only a significant year, it’s a fascinating number! Think of a positive single digit

3. What’s fascinating about 1089? Write any non symmetric three digit number Reverse your original number Express the positive difference as a three digit number Now reverse this difference Then add the above two numbers The answer is…….

4. Learn more about 1089 It’s a perfect square, 33^2 It’s the only four digit number when multiplied by 9 will produce its original number in reversed order: 9801 which is another perfect square, 99^2

5. Become a psychic in 2009 Age by dining out? Pick the number of times a week you would like to dine out (0-7) Times this number by 2 Add 5 to this number Multiply this by 50 If you have already had your birthday this year add 1759, else add 1758 Subtract the four digit year you were born

6. Chocolate Math The above activity could be rephrased as seen in the following link: H:www.matcmadison.edu\jsrisk andara\My documents\Chocolate Math Note, 2009 is NOT prime but 7X7X41

7. Mathemagics and Recreational Mathematics continued….. Mind Reading Super Computation Spelling and the Math connection Predicting a three digit number, house number, card etc.,

8. Is 2009 special? Number a 7X7 square, 1-49 12345671234567 891011121314 15161718192021 22232425262728 29303132333435 36373839404142 43444546474849

9. Interchange rows randomly 15 161718192021 36 373839404142 1 234567 22 232425262728 43 444546474849 891011121314 29 303132333435

10. Now interchange columns randomly 17 211520181619 38 423641393740 3 716425 24 282227252326 45 494348464447 10 1481311912 31 352934323033

11. Add 262 to every entry 279 283 277 282 280 278 281 300 304 298 303 301 299 302 265 269 263 268 266 264 267 286 290 284 289 287 285 288 307 311 305 310 308 306 309 272 276 270 275 273 271 274 293 297 291 296 294 292 295

12. Add the seven numbers on either diagonal, aha! 279+304+263+289+308+271+29 5 = 2009! 281+299+266+289+305+276+29 3 = 2009!

13. For an even more amazing result, Highlight any entry on the table and cross out all the other entries in the same row and column. Continue this process with the remaining entries until you have just seven entries all on different rows and columns.

14. Amazing sum of 2009! 283 301 263 288 310 272 292 272+283+263+310+301+292+283 =2009!!