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The Difference

REDUNDANCY

026210106-1047138354-1552557229-3465121298-0162184810-7
934957619-2257169420-6206692623-1382323643-6586253656-4
380255591-3182956903-7889083073-1254645738-8960248493-9
662510957-4634719653-6322455388-9382165552-3128233861-1
835294951-6622710893-5974836335-5784985389-5375399577-3
595720931-4323051034-3934330330-3990129054-5249231394-3
601454942-4926266123-5586833745-6865646196-2777856084-3
813593346-8522500821-3790028570-2770275210-4571727556-2
438338508-4226107667-1198746793-6374059110-2715205373-7
______  ______  ______  ______  ______

Solution

author: Daniel Low

Redundancy suggests checksum of some sort The 9 digits with a dash and a checksum are ISBN (may not actually point to a book). This is hinted when solver search for the first two entries in the first row. However, the checksum for most of them are wrong.

If we replace each entry with the difference between the wrong checksum and the correct one, each row/column reveals a new entry that is missing the checksum. Calculating the checksums for each column gives an index into the key phrase "REDUNDANCY" and spells out the word erace.

0 026210106 8 1 7
1 934957619 8 2 6
2 380255591 0 3 3
3 662510957 6 4 2
4 835294951 9 6 3
5 595720931 7 4 3
6 601454942 0 4 4
7 813593346 0 8 8
8 438338508 7 4 3
763233483 1
E

0 047138354 6 1 5
1 257169420 0 6 6
2 182956903 1 7 6
3 634719653 0 6 6
4 622710893 6 5 1
5 323051034 8 3 5
6 926266123 1 5 4
7 522500821 6 3 3
8 226107667 3 1 2
566615432 0
R

0 552557229 0 3 3
1 206692623 0 1 1
2 889083073 5 1 4
3 322455388 0 9 9
4 974836335 0 5 5
5 934330330 0 3 3
6 586833745 0 6 6
7 790028570 9 2 7
8 198746793 0 6 6
314953676 6
A 

0 465121298 0 0 0
1 382323643 1 6 5
2 254645738 1 8 7
3 382165552 6 3 3
4 784985389 0 5 5
5 990129054 6 5 1
6 865646196 6 2 4
7 770275210 6 4 2
8 374059110 2 2 0
057351420 8
C

0 162184810 8 7 1
1 586253656 6 4 2
2 960248493 4 9 5
3 128233861 7 1 6
4 375399577 0 3 3
5 249231394 8 3 5
6 777856084 4 3 1
7 571727556 0 2 2
8 715205373 1 7 6
125635126 1
E