This is what I taught Angela and her classmates last year. The one she taught to her older cousin, who taught her teacher in a public school in Malolos. 
Some people might think it is better to just do it the long way - the traditional way. But it is kinda cool to do it this way. More so if the numbers get bigger. Like if there are 12 digits etc. which could not fit in a calculator.
I don't know what it's called (Lattice square? whatever). I picked it up from Dr. Joey from UPLB, during a seminar with FHMS and Ayala Centex.
