My older 2 kids (16 & 14) were both taught some weird lattice method that I never did figure out when they asked me for help with math. As a result, I went with the way I was taught which was the adding the columns and carrying the over the "1" for or multiplying the 1's then the 10's than the 100's etc. putting in an additional zero with each subsequent line and they caught onto that pretty well. They actually lost points on their homework for not showing their work in lattice-form.
They're both better at math than I am, although in my defense I have very little need for anything more than arithmetic and some simple algebra so most of that memory space has been replaced with slightly less useless stuff.