:-)
My experience has shown me that many "sharp" people automatically do this.
454 x 356 =
400 x 300
50 x 50
4 x 6
=
12000 + 2500 + 24 = 14524
This is how both genius kids and autistic number crunchers do it.
I started doing it this way when I was a wee tot....has served me well
Blows people away too so its fun
PS: Nobody taught me this...it just made more sense