IGNITE – Fun with Math

J. SriskandarajahAMATYC Conference

Anaheim, October 31, 2013jsriskandara@madisoncollege.edu

Super Computation

• Think of a 3 digit number, say 270• The final answer, adding four more three digit

numbers to 270 is 2268?• Ask the audience for another 3 digit number, say

581 and you include (the ninth complement) 418.• Ask for one more 3 digit number, say 936 and you

include 063 as your last number.• 270+581+418+936+063 = 2268! Wow!!

Predicting birthday!Mind Reading/Mind Boggling!!

9 27 5 15

25 19 13 1

31 11 21 7

17 3 29 23

3 27 6 31

26 19 14 2

10 23 22 7

18 11 30 15

7 29 6 31

28 5 14 4

12 21 22 15

20 13 30 23

25 31 10 29

24 27 14 8

28 15 13 26

12 11 30 9

Volunteer is asked to point out the tables in which the day of the month he or she was born. The predicted birthday is obtained by adding the entries in the second row, fourth column of the selected tables.

18 29 27 23

24 25 22 16

28 21 26 31

20 17 30 19

Become a psychic!Age by dining out?

• The number of times a week you would like to dine out (0-7)

• Times by 2 then add 5• Now multiply by 50• If you have already had your birthday this year add

1763, else add 1762• Subtract the year you were born• Last two digits your age and the leading digit is the

number of times you plan to dine/week!

Significance of 1776!

• Take any non zero single digit, say 5• Create a three digit number by repeating this number,

555• If President Obama is our 44th president, what is the

ranking of President Lincoln, 16• Multiply 555 by 16 = 8880• Divide this result by your original number, 8880/5 =

1776!• Repeat this for any non zero single digit and stay with 16

as the divisor, end result is 1776, always!!

Predict birthday and age!!

• Birth month times 5, Suppose October, the 10X5 = 50

• Add 6, 50+6 = 56• Times 4, 56X4 = 224• Add 9, 224+9 = 233• Times 5, 233X5 = 1165• Add the day of the month, say October 31, 1165+31

= 1196• Simply subtract 165, 1196-165 = 1031!!

Magic Squares for 2013674 667 672

669 671 673

670 675 668

323 349 320 351 352 318

324 328 344 345 325 347

336 331 333 332 340 341

335 337 339 338 334 330

342 346 327 326 343 329

353 322 350 321 319 348

All these magic squares have the property, sum of all the rows, columns and the

diagonals is 2013!178 239 168 229 158 219 148 209 138 199 128

129 179 240 169 230 159 220 149 210 139 189

190 130 180 241 170 231 160 221 150 200 140

141 191 131 181 242 171 232 161 211 151 201

202 142 192 132 182 243 172 222 162 212 152

153 203 143 193 133 183 233 173 223 163 213

214 154 204 144 194 123 184 234 174 224 164

165 215 155 205 134 195 124 185 235 175 225

226 166 216 145 206 135 196 125 186 236 176

177 227 156 217 146 207 136 197 126 187 237

238 167 228 157 218 147 208 137 198 127 188

Pick any 11 non overlapping numbers and the sum is 2013!

219 215 221 217 211 220 212 213 214 216 218

175 171 177 173 167 176 168 169 170 172 174

241 237 243 239 233 242 234 235 236 238 240

197 193 199 195 189 198 190 191 192 194 196

131 127 133 129 123 132 124 125 126 128 130

230 226 232 228 222 231 223 224 225 227 229

142 138 144 140 134 143 135 136 137 139 141

153 149 155 151 145 154 146 147 148 150 152

164 160 166 162 156 165 157 158 159 161 163

186 182 188 184 178 187 179 180 181 183 185

208 204 210 206 200 209 201 202 203 205 207

Card Trick

Card A 2-10 J Q KCode 1 2-10 11 12 13Suit Club Diamond Heart SpadeCode 6 7 8 9In five steps given below, you can easily predict the unknown card! Let’s roll!!Suppose your participant has an Ace of Spades, which you are not aware.

Step 1. Card Number Ace = 1Step 2. Times 2 1X2 = 2Step 3. Add 1 2+1 = 3Step 4. Times 5 3X5 = 15Step 5. Add the suit 15+9 = 24

Prediction:Simply subtract 5 from above!24 – 5 = 19, last digit = Suit and the remaining

digits indicate the card, Ace of Spades!!!

Three Dice Trick!!!

In this number game, you can predict the three dice your opponent has rolled, which you are not aware.

Perform the following six steps and surprise your opponent:

Suppose the dice are 1, 3 and 6 in this order!

Step 1. First die times 2 1X2 = 2Step 2. Add 5 2+5 = 7Step 3. Times 5 7X5 = 35Step 4. Add the second die 35+3 = 38Step 5. Times 10 38X10 = 380Step 6. Add the third die 380+6= 386

Prediction:Simply subtract 250 = 386-250 = 136!This trick could be extended to any three digit number 000-999!!Try!!!

One for the road…smallest magic square with a magic sum of 2014!

503 506 509 496

508 497 502 507

498 511 504 501

505 500 499 510