Originally Posted by Kriston
For any number times 9, look at the non-9. Subtract 1 and you have the 10s place (so for 9x3 => use 3-1=2). Then use that 2 to figure that 2+?=9. That's 7, so 7 goes in the 1s place for an answer of 27.

Simple and quick, and no fingers! wink

This is cool! I will show DS8 when he's back from school. Hope he doesn't say "I already knew that!".