在一张比例尺为1：20000的地图上如果量出淮海路某段的长度是12厘米那么它的实际长度？ 六年级(1)班共有学生48人,一次数学练习中共有45人合格，...
\u5728\u4e00\u5f20\u6bd4\u4f8b\u4e3a1:20000\u7684\u4e0a\u6d77\u5e02\u5730\u56fe\u4e0a\uff0c\u5982\u679c\u91cf\u51fa\u67d0\u6bb5\u6dee\u6d77\u8def\u7684\u957f\u5ea6\u662f12cm\uff0c\u90a3\u4e48\u8fd9\u6bb5\u6dee\u6d77\u8def\u7684\u5b9e\u964512\u00d720000=240000cm=2.4km
1\u3001\u5408\u683c\u738745\u00f748=93.75%
2\u3001\u7532=50%\u4e59=1/2\u4e59\uff0c\u4e59=2\u7532=200%\u7532
3\u300112/\uff0812+60\uff09=12/72=1/6
4\u3001\uff08100-20\uff09/100=80/100=0.8\uff0c\u6253\u4e868\u6298
5\u30014\u00f752=1/13
6\u30011\u5398\u7c73\u76f8\u5f53200\u7c73
\u5b9e\u9645\u957f\u5ea6\uff1a200\u00d712=2400\u7c73
7\u3001a\u00f7(1-40%)=a\u00f760%=a\u00f73/5=5/3a
8\u3001\uff081\uff09\u5c0648%\u5316\u6210\u6700\u7b80\u5206\u6570\u548c\u5c0f\u6570\u3002
48%=48/100=12/25
\uff082\uff09\u6c424\uff1ax=1\u53c82\u5206\u4e4b1\uff1a1\u4e2d\u7684x
4\u2236x=3/2\u22361
3/2x=4
x=8/3
\uff083\uff09\u6c42x\u7684\u503c\uff1a1.2\u5206\u4e4bx=2\u5206\u4e4b6.25\u3002
1.2x=6.25/2
x=6.25/(2\u00d71.2)=6.25/2.4=125/48
\uff084\uff09\u5df2\u77e5a\uff1ab=4\uff1a5\uff0cb\uff1ac=0.5\uff1a3\u5206\u4e4b2\uff0c\u6c42a\uff1ab\uff1ac
a\u2236b=4\u22365
b\u2236c=0.5\u22362/3=5\u223620/3
\u2234a\uff1ab\uff1ac=4\u22365\u223620/3=12\u223615\u223620
12÷1/20000
=240000厘米
=2.4千米
12*20000=240000cm=2400m
绛旓細璁捐繖涓湴鍖虹殑瀹為檯闈㈢Н鏄痻m2锛屸埖12cm2=0.0012m2锛屸埓锛120000锛2=0.0012x锛屸埓x=480000m2锛庣敤绉戝璁版暟娉曡〃绀轰负锛4.8脳105m2鏁呯瓟妗堜负锛4.8脳105锛
绛旓細12梅1/20000 =240000鍘樼背 =2.4鍗冪背
绛旓細AB涔嬮棿鐨勫疄闄呰窛绂讳负锛8.5鍘樼背梅锛1:20000锛=170000鍘樼背=1.7鍗冪背 鈭碅瀹為檯澶勪簬B鍦扮殑鍖楀亸涓60掳鏂瑰悜1.7鍗冪背鐨勫湴鏂
绛旓細24梅2=12锛堝帢绫筹級5+3=812脳58=7.5锛堝帢绫筹級12脳38=4.5锛堝帢绫筹級7.5梅120000=150000锛堝帢绫筹級4.5梅120000=90000锛堝帢绫筹級150000鍘樼背=1500绫90000鍘樼背=900绫1500脳900=1350000锛堝钩鏂圭背锛1350000骞虫柟绫=135鍏》绛旓細杩欏潡璇曢獙鐢板疄闄呴潰绉槸135鍏》锛庢晠绛旀涓猴細135锛
绛旓細瑙ｏ細鍦板浘涓婇噺寰椾竴鍧楅暱鏂瑰舰鐢板湴鐨勯暱鏄8鍘樼背锛屽4鍘樼背锛屽垯瀹為檯涓婇暱鏄8脳20000=160000鍘樼背锛屽嵆1.6鍗冪背锛屽疄闄呭鏄4脳20000=80000鍘樼背锛屽嵆0.8鍗冪背 鎵浠ヨ繖鍧楅暱鏂瑰舰鐢板湴瀹為檯闈㈢Н鏄1.6脳0.8=1.28骞虫柟鍗冪背
绛旓細鍦ㄤ竴骞呮瘮渚嬪昂鏄1锛20000鐨鍦板浘涓婏紝閲忓緱AB涓ゅ湴闀8鍘樼背銆傚鏋滃湪姣斾緥灏烘槸1锛40000鐨勫湴鍥句笂锛岃繖涓ゅ湴鐨勮窛绂绘槸40000:20000=4cm
绛旓細2.8鍘樼背*20000=560绫 560/2锛5+2锛=40 闀匡細5*40=200绫 瀹斤細2*40=80绫 鎿嶅満闈㈢Н=200*80=16000骞虫柟绫
绛旓細姣斾緥灏=鍥句笂璺濈锛氬疄闄呰窛绂 1:20000=5cm锛氬疄闄呰窛绂 瀹為檯璺濈=5cm脳20000 1:5000=x锛氬疄闄呰窛绂 5000x=瀹為檯璺濈=5cm脳20000 x=5cm脳20000/5000=20cm
绛旓細浣犲ソ锛氬疄闄呴暱=3脳20000=60000锛堝帢绫筹級=600锛堢背锛夊疄闄呭=2脳20000=40000锛堝帢绫筹級=400锛堢背锛夊疄闄呴潰绉=600脳400=240000锛堝钩鏂圭背锛
绛旓細鍦姣斾緥灏轰负1:20000鐨鍦板浘涓婏紝3鍘樼背鐨勮窛绂诲疄闄呯瓑浜 3梅1/20000=60000锛堝帢绫筹級=600锛堢背锛夈600绫筹紙60000鍘樼背锛夌殑璺濈鍦ㄦ瘮渚嬪昂涓1:30000鐨勫湴鍥句笂鐨勮窛绂讳负锛60000脳1/30000=2锛堝帢绫筹級銆
