[TheConservativeParty]

Gee that is odd, and it works until 9 x 11. How'd we get this old and not notice that.🙃

[CJ Wolf]

yeah, never noticed. I always had an easy time with 9 X. I’d do 10 X and subtract the X. 10 X 4 = 40 - 4 = 46 = 9 X

[MileHi]

Gee that is odd, and it works until 9 x 11

Ummm...

9 x 11 = 99

9 + 9 = 18

1 + 8 = 9

Have no idea how long that holds. Helped me in grade school

[bagster]

Gee that is odd, and it works until 9 x 11. How'd we get this old and not notice that.🙃

9 x 11 = 99

9 + 9 = 18

1 + 8 = 9

Ta da!

9 is a magical number.

[lyby]

Gee that is odd, and it works until 9 x 11.

*************************

Ah, but the pattern does indeed continue when you add the digits of each product and then add the digits of each sum:
9 x 11 = 99, then 9 + 9 = 18, and 1 + 8 = 9
9 x 12 = 108, then 1 + 0 + 8 = 9
...
9 x 76 = 684, then 6 + 8 + 4 = 18, and 1 + 8 = 9
...
9 x 7857 = 70,713, then 7 + 0 + 7 + 1 + 3 = 18, and 1 + 8 = 9

Try it! Warning: can be addictive. (smile)