大學(xué)英語綜合教程第一冊 Unit 8b

[00:00.00] benefit\ in the first place\ proceed\ competent [00:04.00]利益\首先\繼續(xù)進(jìn)行\(zhòng)有能力 [00:07.99]essential\ concentrate on\ solve\ efective [00:12.21]必要的\集中\(zhòng)解決\有效的 [00:16.43]confuse\ what if\ focus\ at hand [00:20.75]使困惑\如果…怎么樣\集中注意力\在手邊 [00:25.08]claim\ contribute\ ultimate [00:31.11]Do you think the use of calculators inleapning math is a good idea? [00:37.15]If you do,perhaps this artic will change your mind. [00:41.98]DITCH THE CALCULATOR by Diane Hunsaker [00:47.83]I sigh inwardly as I watch yet anotber student,this one a ninth grader [00:49.45]struggle with an advanced math problem that requires simple multiplication. [00:57.39]He mentally battles with5×6×6 [01:02.25]looks longly at the off-limits calcu-lator on the corner of my desk and fina1y guesses the answer:35 [01:13.09]The rowth in the use of calculators in the classroom amazes me. [01:18.45]The students I tutor tell me regularly [01:22.60]that their teachers allow unlimited access to this tool [01:28.22]The National Coulcil of Teachers 0f Mathematics actiVely encourages its use. [01:35.37]Recently I attended a math seminar [01:38.93]where the instructor casually stated that teachers were no longer reluctant [01:45.82]to permit calculators in the classroom [01:49.30]Now "everyone" agrees on their importance,she said [01:55.23](1) The more I hear from the education esablishment [01:59.77]about the benefits of these devices in schools,the 1ess surprised I am [02:05.70]when midle and high-school students [02:09.46]who have difficulty with arithmetic call for toring in algebra and geometry [02:15.50]Having worked six years as an electrical engineer before switching to teaching [02:22.50]I often suggest to my students that they consider technical and scientific careers [02:29.63]but I'm d1iscouraged when I see an increasing number of kids [02:35.56]who lack simple math skills. [02:38.80]Educators have many arguments in defense of calculators, [02:44.68]but each one ignores the reason that we teach math in the first place [02:50.55]Math trains the mind. [02:53.87]By this I mean that students learn to think logically and rationally [02:59.23]to proceed from known information to desired information [03:04.82]and to become competent with both numbers and ideas [03:09.57]These skills are something that math and science teach [03:15.11]and are essential for adolescents to become thinking [03:19.68]intelligent members of society. [03:23.34]Some teachers argue that calculators let students concentrate on [03:30.08]how to solve problems instead of getting tied up with tedious computations [03:37.23](2) Having a calculator doesn't make it any easier [03:42.07]for a student tn decide how to attack a math nrohlem [03:46.74]Rather,it only encourage him to try every combination of addition, subtraction [03:54.48]Multiplication or division [03:58.29]without any thought about which would be more appropriate [04:02.65]Some of my elementary-school children look at a word problem [04:08.84]and instantly guess that adding is the correct approach [04:13.60]When I suggest that they solve the problem this way without a calculator, [04:20.81]they usually pause and think before continuing [04:24.65]A student is much more likely to cut down his work by reflecting on the problem first [04:33.87]if he doesn't have a calculator in his hand. [04:39.59]Learning effective methods for approaching confusing problems [04:45.91]is essential,not just for math but for life. [04:50.06]A middle-school teacher once said to me, [04:55.63]"So what if a student can't do long division? [04:59.39]Give him a calculator,and he'll be fine." [05:03.05]I doubt it.I don't know when learning by heart and repetitious problem [05:10.99]solving fell to Such a low priority in education circles [05:15.85]How could we possibly communicate with each other,much less create new ideas [05:24.39]without the immense store of information in our brains? [05:30.89]Math is as much about knowing why the rules work as knowing what the roles are [05:40.25]A student who cannot do long division obviously does not comprehend the principles on which it is based [05:49.81]A true understanding of why often makes learning by rote unnecessary, [05:58.35]because the student can figure out the rules himselt [06:02.61]My students who view the multiplication tables as a list of unrelated numbers [06:10.55]have much more difficulty in math than those [06:14.62]who know that multiplication is simply repeated addition [06:21.28]Calculators prevent students from seeing this kind of natural structure and beauty in math [06:31.00]A student who learns to handle numbers mentally can focus [06:38.08]on how to attack a problem and then complete the actual calculations easily [06:45.24]He will also have a much better idea of what the answer should be [06:51.77]since experience has taught him"number sense,"or the relationship between numbers. [07:00.39]A student who has grown up with a calculator [07:05.95]will struggle with both strategies and computations. [07:10.81]When youngsters used a calculator to solve 9×4 in third grade, [07:19.07]they are still using one to solve the same problem in high school. [07:27.01]By then they are also battling with algebra [07:30.95](3) Because they never felt comfortable working with numbers as children, [07:38.40]they are seriously disadvantaged when they attempt the generalized math of algebra [07:46.26]Permitting extensive use of calculators invites a child's mind to stand still. [07:55.61]If we don't require students to do the simple problems that calculators can do [08:04.86]how can we expect them to solve the more complex problem [08:11.68]that calculators cannot do? [08:14.55]Students learn far more when they do the math themselves. [08:21.71]I've tutored youngsters on practice SAT exams [08:27.56]where they immediately reach for their calculators. [08:33.83]If they'd take a few seconds to understand the problem at hand [08:39.39]they most likely would find a simpler solution without needing a stick to lean on [08:48.01]I have also watched students incorrectly [08:52.66]enter a problem like 12 + 32 into their calculators as 112 + (32×32) [09:04.29]and not bat an eye at the obviously incorrect answer. [09:12.05]After all,they useo al calculator,so it must be right. [09:17.09]Educators also claim that calculators are so inexpensive and commonplace [09:24.79]that students must become competent in using them. [09:31.25]New math texts contain whole sections on solving problems with a calculator. [09:39.61]Most people,including young children,can learn its basic functions in about five minutes [09:46.74]Calculators do have their place in the world outside school and, [09:54.29]to a limited extent, in higher-level math classes [09:58.36]but they are hardly education tools. [10:03.51]Many teachers as well as students insist, [10:09.88]"Why shouldn't we use calculators?They will always be around [10:14.84]and we'll never do long division in real life. [10:20.30]"This may be true.It's true of most math [10:24.27]Not many of us need to figure the circumference of a circle [10:30.94]or factor a quadratic equation for any practical reason [10:35.98]But that's not the sole purpose of teaching math. [10:41.72](4)We teach it for thinkin and discipline,both of which expand the mind [10:48.18]and increase the student's ability to function [10:52.93]as a contributing individual in society:the ultimate goals of education

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