This video is mostly a straight up guide.
Have any of you heard of this before now, because I certainly hadn't.
Some further reading
Further Guide: http://www.education.vic.gov.au/school/teachers/teachingresources/discipline/maths/continuum/Pages/latticemulti.aspx This one says that this method comes from Italy and was introduced by Fibonacci! Despite it being called frequently the "Chinese Window" style of multiplication, so some conflicting theories.
More conflicting backgroud: http://rationalmathed.blogspot.co.uk/2007/10/who-invented-lattice-multiplication.html So bits of this text say it originated from India?
Please tell if I'm living in the Stone Age with this, since I've only just discovered it.