tlh@cs.purdue.EDU (Thomas L. Hausmann) (02/28/88)
In article <24997@cca.CCA.COM>, g-rh@cca.CCA.COM (Richard Harter) writes: > In article <7301@tut.cis.ohio-state.edu> zwicky@pterodactyl.cis.ohio-state.edu (Elizabeth D. Zwicky) writes: > > ... > >up was that he was doing cross-multiplication, just like the books have > >you do. That gets good scores on tests, because it looks right. I > >was moving the decimal place to get 10% and then multiplying that, > >which math teachers fail because the intermediate steps aren't "right" > >but it sure works.) > One question -- what did you mean by cross multiplication. To > me, this means the following method. Example: > 523 > 469 > --- > 245287 > <two methods given for hand solution> I use a mental chalkboard and visualize myself working the problem by hand. i.e. 523 469 --- 4707 3138 2092 ------ 245287 One's capacity to do this is probably limited. I haven't "pushed it" to see how big of numbers I can handle. ------------------------------------------------------------------------------- Tom Hausmann Dept. of Computer Sciences Purdue University tlh@mordred.cs.purdue.edu | My ideas? There has never been an original ...!purdue!tlh | thought since Plato.