These MAGATs brains are like Schrodinger's cat if it were to have escaped from its box but had managed to maintain its uncollapsed quantum state of being simultaneously alive and dead.

especially for a more complicated calculation. What I was describing was some mental shortcuts I can take for something that is just difficult enough that I can't do the old school method in my head, but not so difficult that I can't do it in my head at all. I break the problem down into a few chunks that I can keep track of without writing anything down. Now if you'd asked for 438*113, I'd be going for the pen and paper, or a calculator.

In my head, I think,

8 x 113 =
8 x (100 + 10 + 3) =
800 + 80 + 24 =
880 + 24 =
904

or alternately, handling the 10's place first,

8 x 113 =
8 x (11 * 10) + 8 * 3 =
88 * 10 + 24 =
88 * 10 + 2 * 10 + 4 =
90 * 10 + 4 =
904

Something like 8 * 98 is easy, since it's 8 * (100 - 2) = 800 - 16 = 784.

But then, I think I was born odd.