On 18 January 2014 00:22, George Smith wrote: > I have struggled to test the graphical method multiplying a 2 digit > number by a three digit - e.g 34 x 192. > And how do you do e.g. 100 x 100? > Seems to work OK. To work out what sums to what when doing it graphically, first do the expanded numeric equivalent t too what goes where - or, if you were Sir IsaacNewton you would just visualise this instantly :-). 34 x 123 =3D(30 + 4) x (100+20 + 3) =3D [30.100] + [30.20 + 4.100] + [30.3 + 4.20] + 4.3 Graphically the pairs of middle terms in the same set lie above each other vertically. _____________________ 100 x 100 Draw dotted lines for zeros Proceed as before. N x dotted =3D 0 Sums along edge =3D 1 0 0 0 0 =3D 10,000. _____________ Playing sheet - rough - was not drawn with show & tell in mind :-) - http://bit.ly/zzz_GraphicalMethod Russell --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .