Symmetry of Digit "2" In Squaring--- by Piyush Goel
If we square 11, it is very simple put 1(2*1) (12) get 121 same as square 12 put 1(2*2)(22) get 144 again for 13 we get 169 and for 14 we get 1 8 16=196 and so on.
When we go deep, we find that there is symmetry of two types
(2, 4, 6, 8, 10, 12, 14, 16, 18, 20 …. Diff is always 2) &
(1, 4 , 9 , 16, 25, 36, 49, 64, 81, 100 ) diff. is 3 5 7 9 11 13 15 17 19 and diff. of 3 5 7 9 11 always 2, so there is true symmetry .
Up to 19 it is right but at 20 how we can put 1 20 100 just because of symmetry.
11^2 = 1 2 1
12^2 = 1 4 4
13^2 = 1 6 9
14^2 = 1 8 16 = 100 + 80 + 16 = 196
15^2 = 1 10 25 = 100 + 100 + 25 = 225
16^2 = 1 12 36 = 100 + 120 + 36 = 256
17^2 = 1 14 49 = 100 + 140 + 49 = 289
18^2 = 1 16 64 = 100 + 160 + 64 = 324
19^2 = 1 18 81 = 100 + 180 + 81 = 361
20^2 = 1 102 = 1 20 100 = 100 + 200 + 100 = 400
21^2 = 1 112 = 1 22 121 = 100 + 220 + 121 = 441
22^2 = 1 122 = 1 24 144 = 100 + 240 + 144 = 484
23^2 = 1 132 = 1 26 169 = 100 + 260 + 169 = 529
24^2 = 1 142 = 1 28 196 = 100 + 280 + 196 = 576
25^2 = 1 152 = 1 30 225 = 100 + 300 + 225 = 625
26^2 = 1 162 = 1 32 256 = 100 + 320 + 256 = 676
27^2 = 1 172 = 1 34 289 = 100 + 34 + 289 = 729
28^2 = 1 182 = 1 36 324 = 100 + 360 + 324 = 784
29^2 = 1 192 = 1 38 361 = 100 + 380 + 361 = 841
30^2 = 1 202 = 1 40 400 = 100 + 400 + 400 = 900
There is a symmetry,he got a method, which is shown as below for 31, 41, 51 and so on.
31^2 = 1 212 = 1 42 (1 11)2 = 1 42 (1 22 121)
= 961 = 121 + 220 + 100
= 441 + 420 + 100 = 961
41^2 = 1 312 = 1 62 (1 21)2 = 162 (1 42) (1 11)2
= 1 62 (1 42) (1 22 121)
= 1 62 (961) = 961 + 620 + 100 = 1681
51^2 = 1 412 = 1 82 (1 31)2 = 1 82 (1 62) (1 21)2
= 1 82 (1 62) (1 42) (1 11)2
= 1 82 (1 62) (1 42) (1 22 121)
= 1 82(1681) = 1681 + 820 + 100 = 2601
61^2 = 1 512 = 1 102 (41)2 = 1 102 (1 82) (1 31)2
= 1 102 (1 82) (1 62) (1 21)2
= 1 102 (1 82) (1 62) (1 42) (1 11)2
= 1 102 (1 82) (1 62) (1 42) (1 22 121)
= 1 102 (2601) = 2601 + 1020 + 100 = 3721
71^2 = 1 612 = 1 122 (1 51)2 = 1 122 (1 102) (41)2
= 1 122 (1 102) (1 82) (1 31)2 = 1 122 (1 102) (1 82) (1 62) (1 21)2
= 1 122 (1 102) (1 82) (1 62) (1 42)(1 11)2
= 1 122 (1 102) (1 82) (1 62) (1 42) (1 11)2
= 1 122 (1 102) (1 82) (1 62) (1 42) (1 22 121)
= 3721 + 1220 + 100 = 5041
81^2 = 1 712 = 1 142 (1 612) = 1 122 (1 51)2 = 1 122 (1 102) (41)2
= 1 122 (1 102) (1 82) (1 31)2 = 1 122 (1 102) (1 82) (1 62) (1 21)2
= 1 122 (1 102) (1 82) (1 62) (1 42)(1 11)2
= 1 122 (1 102) (1 82) (1 62) (1 42) (1 11)2
= 1 122 (1 102) (1 82) (1 62) (1 42) (1 22 121)
= 5041 + 1420 + 100 = 6561
91^2 = 1 812 = 1 162(1 712 ) = 1 142 (1 612) = 1 122 (1 51)2
= 1 122 (1 102) (41)2 = 1 122 (1 102) (1 82) (1 31)2
= 1 122 (1 102) (1 82) (1 62) (1 21)2
= 1 122 (1 102) (1 82) (1 62) (1 42)(1 11)2
= 1 122 (1 102) (1 82) (1 62) (1 42) (1 11)2
= 1 122 (1 102) (1 82) (1 62) (1 42) (1 22 121)
= 6561 + 1620 + 100 = 8281
101^2 = 1 912 = 1 182(1 812) = 1 162(1 712 ) = 1 142 (1 612) = 1 122 (1 51)2
= 1 122 (1 102) (41)2 = 1 122 (1 102) (1 82) (1 31)2
= 1 122 (1 102) (1 82) (1 62) (1 21)2
= 1 122 (1 102) (1 82) (1 62) (1 42)(1 11)2
= 1 122 (1 102) (1 82) (1 62) (1 42) (1 11)2
= 1 122 (1 102) (1 82) (1 62) (1 42) (1 22 121)
= 8281 + 1820 + 100 = 10201

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