Arithmetic Curiosities

- Here are just a few interesting patterns in arithmetic that you or your students may explore. Verify these results with paper and pencil or with calculator (if you must):

1 x 9 + 2 = 11	9 x 9 + 7 = 88	9 x 9 = 81	6 x 7 = 42
12 x 9 + 3 = 111	98 x 9 + 6 = 888	99 x 99 = 9801	66 x 67 = 4422
123 x 9 + 4 = 1111	987 x 9 + 5 = 8888	999 x 999 = 998001	666 x 667 = 444222
1234 x 9 + 3 = 11111	9876 x 9 + 4 = 88888	9999 x 9999 = 99980001	6666 x 6667 = 44442222
12345 x 9 + 6 = 111111 123456 x 9 + 7 = 1111111 1234567 x 9 + 8 = 11111111 12345678 x 9 + 9 = 111111111 123456789 x 9 +10= 1111111111	1 x 8 + 1 = 9 12 x 8 + 2 = 98 123 x 8 + 3 = 987 1234 x 8 + 4 = 9876 12345 x 8 + 5 = 98765 123456 x 8 + 6 = 987654 1234567 x 8 + 7 = 9876543 12345678 x 8 + 8 = 98765432 123456789 x 8 + 9 = 987654321	9 x 9 + 7 = 88 98 x 9 + 6 = 888 987 x 9 + 5 = 8888 9876 x 9 + 4 = 88888 98765 x 9 + 3 = 888888 987654 x 9 + 2 = 8888888 9876543 x 9 + 1 = 88888888 98765432 x 9 + 0 = 888888888	1 x 1 = 1 11 x 11 = 121 111 x 111 = 12321 1111 x 1111 = 1234321 11111 x 11111 = 123454321 111111 x 111111 = 12345654321 1111111 x 1111111 = 1234567654321 11111111 x 11111111 = 123456787654321 111111111 x 111111111= 12345678987654321