MULTI-DIGIT MULTIPLICATION WEBSITES

WHAT'S WRONG? http://www.topmarks.co.uk/Flash.aspx?f=WhatsWronggrid
Spot what is wrong in the multiplication calculation. Two digit multiplication by a single digit and also by double digits.

PARTIAL PRODUCTS ALGORITHM TUTORIAL
http://www.prometheanplanet.com/en/Resources/Item/139294/how-do-you-multiply-a-two-digit-number-by-a-two-digit-number-using-partial-products#.T4Od2tXYT4w

A LITTLE HISTORY http://www.prometheanplanet.com/en/Resources/Item/36558/napiers-bones#.T4Oed9XYT4w
History of Lattice Multiplication