Name School Team

Event 3: Logic and Reasoning (with calculators) 5th/6th grade Math Meet ‘08
For each number pattern, fill in the next five terms. (2 pts. each blank)
ANSWER KEY
1st
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2nd
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3rd
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4th
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5th
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6th
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7th
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8th
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9th
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10th
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1)
2)
3)
4)
1 2 5 10 17 26 37 50 65 82
1 2 6 15 31 56 92 141 205 286
1 3 9 19 33 51 73 99 129 163
1 4 11 24 43 72 109 152 205 266

1 answer

1 2 5 10 17 26 37 50 65 82

If you subtract 1 from every number is should be obvious.

0 1 4 9 16 25 36 64 81

These are the perfect squares. So the answer is:

n ^ 2 + 1

Next nunbers :

10 ^ 2 + 1 = 100 + 1 =101

11 ^ 2 + 1 = 121 + 1 = 122

13 ^ 2 + 1 = 169 + 1 = 170

14 ^ 2 + 1 = 196 + 1 = 197

15 ^ 2 + 1 = 225 + 1 = 226

1 4 9 16 31 56 92 141 205 286

In the second pattern, the differences are 1,4,9,16,25,36,49,64,81 which are square numbers.

Next nunbers :

286 + 10 ^ 2 = 286 + 100 = 386

386 + 11 ^ 2 = 386 + 121 = 507

507 + 12 ^ 2 = 507 + 144 = 651

651 + 13 ^ 2 = 651 + 169 = 820

820 + 14 ^ 2 = 820 + 196 = 1016

1 3 9 19 33 51 73 99 129 163

2 n ^ 2 + 1

Next numbers:

2 * 10 ^ 2 + 1 = 2 * 100 + 1 = 200 + 1 = 201

2 * 11 ^ 2 + 1 = 2 * 121 + 1 = 242 + 1 = 243

2 * 12 ^ 2 + 1 = 2 * 144 + 1 = 288 + 1 = 289

2 * 13 ^ 2 + 1 = 2 * 169 + 1 = 338 + 1 = 339

2 * 14 ^ 2 + 1 = 2 * 196 + 1 = 392 + 1 = 393

1 4 11 24 43 72 109 152 205 266

The differences are 3,7,13,19,29,37,43,53,61

which are every other prime number

Nex numbers :

266 + 67 = 333

333 + 73 = 406

406 + 83 = 489

489 + 97 = 586

586 + 103 = 689