bulko@ut-sally.UUCP (Bill Bulko) (03/05/88)
In article <8314@eleazar.Dartmouth.EDU> roberta@eleazar.Dartmouth.EDU (Roberta Millstein) writes: > >Is anyone else here *unable* to do mental arithmetic? Yes, I had all the >drills, etc, etc, and have absolutely no problem with a pencil and paper, but >as soon as I try to keep more than two numbers in my head, I'm lost. I can >manage the bit about doing the decimal point, and can keep a running total of >groceries if I round to the nearest dollar--but even the latter takes some >concentration. Forget multiplying in my head, I can't remember where I've >been. Is this just me or what? It's not just you. I'm very good at handling numbers; given pencil and paper (or sufficiently small numbers) I can whip through calculations very quickly. But sometimes I feel like I was born without any registers in my CPU: I cannot store any numbers (beyond a couple of digits) for later use! In computing 15% tips, for instance, I use the 10% + 5% method that everyone [who's anyone :-)] uses, but the memory is the problem: by the time I've computed the 5% part, I've forgotten what the result of the 10% computation was (or vice versa). It takes me much longer than necessary to do things like this in my head, since I have to "recite" subtotals several times to commit them to more permanent memory before I move on. What an annoyance. >>P.S. By the way, the same goes for doing arithmetic long hand. When's >>the last time you balanced your checkbook by hand? > >Actually, believe it or not, I almost always do it by hand. It's too annoying >to have to worry about whether or not I've pressed the right keys. I can >do it much faster and more accurately by hand. With a pen. ;-) Me too. I trust my calculations considerably more than I trust my accuracy in keying in the numbers; besides, the calculator slows me down. For most everyday calculations, it takes me longer to go get a calculator (even if it's in the same room as me) than it does to do the calculation on paper. I only use calculators for: - multiplications, divisions, and higher functions - addition/subtraction of more than two large numbers, where I would otherwise have to write down the subtotal in lieu of memorizing it. And yes, I use a pen in my checkbook, too. :-) Does anyone else besides me prefer adding/subtracting numbers from left to right (for checkbook-sized numbers or smaller)? (Of course, this depends on your balance. . .) I sometimes get funny looks from people who watch me writing totals from left to right as though I were writing English. (I have no trouble storing a series of carries along a ten-digit number. . . maybe that's it! I only have one register, but I can access the bits individually!) Bill _______________________________________________________________________________ Artificial Intelligence: the art of making computers that behave like the ones in movies Bill Bulko The University of Texas bulko@sally.UTEXAS.EDU Department of Computer Sciences _______________________________________________________________________________