簡便運算的練習(xí)題和答案

1、創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克,運算定律練習(xí)題(1)乘法交換律：aXb=bXa乘法結(jié)合律：(aXb)Xc=aX(bXc)38X25X442X125X825X17X4(25X125)X(8X4)(2)乘法交換律和結(jié)合律的變化練習(xí)125X64125X8844X2525X28(3)加法交換律：a+b=b+a加法結(jié)合律：(a+b)+c=a+(b+c)357+288+143158+395+105167+289+33129+235+171+165378+527+73169+78+2258+39+42+61138+293+62+107(4)乘法分配律：(a+b)Xc=aXc

2、+bXc正用練習(xí)49X4X538X125X8X3(125X25)X45X289X2(125X12)X8125X(12X4)125X2458X101-58創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克*【思路導(dǎo)航】在除法里,被除數(shù)和除數(shù)同時乘或除以一個相同的數(shù),商不變.325 25(80+4)X2515X(20+3)(20+4)X25(125+17)X825X(40+4)5乘法分配律正用的變化練習(xí)：36x325x4139x101201X24125x88(6)乘法分配律反用的練習(xí)：34X72+34X2835X37+65X3785X82+85X1825X97+25X376X25+2

3、5X24(7)乘法分配律反用的變化練習(xí)：38X29+3875X2994-7564X199+6435X68+68+68X64思考題：8其他的一些簡便運算.800 256000+1253600+8+574X99=(325x4)v(25x4)=1300+100=13【練一練1】(1)450 253500X25【經(jīng)典例題二】計算25x125x4x8【思路導(dǎo)航】如果先把25與4相乘,可以得到100,同時把125與8相乘,可以得到1000;再把100和1000相乘就可以了.運用了乘法交換律和結(jié)合律.25x125x4x8=(25x4)x125x8)=100 x1000=100000【練一練2(1)125x1

4、5x8x4(2)25x24(3)125x16【經(jīng)典例題三】計算：(1)125x34+125x66(2)43x11+43x36+43x52+43【思路導(dǎo)航】利用乘法分配律來計算這兩題(1)125x34+125x66(2)43x11+43x36+43x52+43=125x(34+66)=43x(11+36+52+1)=125x100=43x10021x73+26x21+21【經(jīng)典例題四】計算(D(360+108)-36(2)525+25(3)(4)10000 6259000+225(5)495004-900(6)(4)75x1625x5x64x125(5)125x25x32=12500【練一練3】

5、計算下面各題:(1)125x64+125x36=4300(2)64x45+64x71-64x16(2)Iv2+3v2+5v2+7v2【思路導(dǎo)航】兩個數(shù)的和、差除以一個數(shù),可以用這個數(shù)分別去除這兩個數(shù),再求出兩個商的和(差利用這一性質(zhì),可以使計算簡便.(1)(360+108)+36(2)1+2+3+2+5+2+7+2=360+36+108+36=(1+3+5+7)+2=10+3=16+2=13=8【練一練4】(1)(720+96)+24(2)(4500-90)+45(3)6342+21(5)73+36+105+36+146+36(6)(10000-1000-100-10)+10【經(jīng)典例題五】15

6、8x61+79x3【思路導(dǎo)航】在乘除混合運算中,如果算式中沒有括號,計算式可以根據(jù)運算定律和性質(zhì)調(diào)換乘數(shù)或者除數(shù)的位置,只要計算：數(shù)字跟著前面的符號一起移動.158x61+79x3=1584-79x61x3=2x61x3=366【練一練5】計算下面各題：(1)238x36+119x5(2)138x2769x50【經(jīng)典例題六】計算下面各題：(1)103x96+16(2)200+(25X)【思路導(dǎo)航】這兩道題都是乘除法混合運算,我們可以根據(jù)這兩道題的特點,采用加括號和去括號的方法,使計算簡便.可以概括為：括號前是乘號,加、去括號不改號,括號前是除號,田、去括號要改號.(1)103x964-16(2

7、)200+(25+4)=103x(96X6)=200+25x4=103x6=8x4=618【練一練6】計算下面各題:(1)612x3664-183(4)8811+89(3)624x48+312+8(4)406x312X04+203=32(2)1000+(125+4)(4)241x345-r678v345x(678+241)【經(jīng)典例題七】計算：(D68x62(2)85x85【思路導(dǎo)航】這兩題的形式叫做“頭同尾合十它們的計算方法是：先用兩個因數(shù)的個位數(shù)相乘,并把積直接寫在末尾,如果積不滿10,十位上要補寫0,然后再將兩個因數(shù)的十位數(shù)乘它本身加1的和,積寫在兩個個位數(shù)積的前面.(1)68x62第一步

8、8x2=16,第二步6x(6+1)=42,合起來是4216(2)85x85第一步5x5=25,第二步是8x(8+1)=72,合起來是7225【練一練7】(1)23x27(2)46x44(3)55x55(4)91x99【經(jīng)典例題八】計算：26x11【思路導(dǎo)航】一個兩位數(shù)乘11的方法是：用兩位數(shù)的頭作積的頭,用兩位數(shù)的尾作積的尾,用這個兩位數(shù)的兩個數(shù)字之和作積的中間數(shù)(如果相加滿十,那么把和的十位數(shù)“小加到頭上.26x11第一步2作積的頭,第二步6作積的尾,第三步2+6=8作中間,合起來是286o【練一練8計算(1)53x11(2)39x11(3)65x11(4)98x11【經(jīng)典例題九】計算：35

9、8x11【思路導(dǎo)航】 三位數(shù)乘U,用三位數(shù)的頭作積的頭,用三位數(shù)的尾作積的尾,用三位數(shù)前兩位數(shù)字組成的數(shù)加厚兩位數(shù)字組成的數(shù)的和作積的中間數(shù).358x11,第一步用3作積的頭,第二步用8作積的尾,在用35+58=93,合起來是3938.【練一練9】計算(1)353x11(2)654x11(3)896x11(3)(13x8x5x6)-r(4x5x6)(4)75x16(5)125x25x32(6)25x5x64x125【練一練3】計算下面各題:(1)125x64+125x3621x73+26x21+21(2)64x45+64x71-64x16(3)【練一練4141(1)(720+96)6342+2

10、1 24(2)(4500-90)X5(3)(4)8811+89(10000-1000-100-10)+10(5)73+36+105+36+146+36(6)【練一練5】計算下面各題:創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克*(4)100004-625(5)49500+900(6)9000+225【練一練2】(1)125x15x8x4(2)25x24【練一練1】(1)450+25(2)525+25(3)3500X25(3)125x16簡便計算專題練習(xí)(181+2564)+2719378+44+114+242+222276+228+353+219(3)624x48+312+

11、8(4)406x312X04+203【練一練6】計算下面各題:(1)612x366X83(2)1000-r(125+4)(3)(13x8x5x6)v(4x5x6)(4)241x345-r678v345x(678+241)【練一練7(1)23x27(2)46x4491x99(3)55x55(4)【練一練8】計算(1)53x11(2)39x1198x11(3)65x11(4)【練一練9】計算(1)353x11(2)654x11(3)896x11158+262+138375+219+381+2255001-247-1021-232(375+1034)+(966+125)99+999+9999+999

12、99(2130+783+270)+10177755-(2187+755)10652214+638+2863065-738-899+344-2142357-183-317-3572365-1086創(chuàng)作編號:BG7531400019813488897sx創(chuàng)別如克*497-2991883-398138x25x42370+199512x253999+49875x24(13x125)x(3x8)(12+24+80)x50178x101-17883x102-83x2123x3+85x12350 x(34x4)x379x42+79+79x5716800-12021500-12549700.7004800+2

13、584x36+64x8498x19925x(24+16)7300-25430100-？210012484-24704x25簡便計算練習(xí)題225x32x12532x(25+125)88x125102x7658x9875x99+2x75123x18-178x99+1788100:4+7532000-4003150+15簡便計算練習(xí)題32356-(1356-721)1235-(1780-1665)75x27+19x2531x870+13x3104x(25x65+25x28)(300+6)x12(13+24)x825x(4+8)125x(35+8)84x101504x2578x10225x20499x

14、64999x9999x16638x9999X13+1378X4+78X3+78X325+199X2532X16+14X32125X32X825X32X12588X12572X1253600+25+41250+25+5簡便計算練習(xí)題48100M3753000E25出1200-624-76847-527-2732100-728-772273-73-27278+463+22+37425+14+186732+580+2681034+780320+102214-(86+14)(155+230)787-(87-29)365-(65+118)455.576-285+85825-657+57690-177+7

15、7755-287+87創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克/871-299157-99363-199968-599178X101-17883X102-83X217X23-23X735X127-35X16-11X35簡便計算練習(xí)題5容易出錯類型共五種類型600-60-15736-35X2020X4+20X425X405X417575:2580-20X2+6036-36-6-6100+45-100+45100+1-100+11000+8-1000+825X845X836X9:36X925X8.15X97+348X99+15+95X28102+1-102+125+75-2

16、5+7540+360-20-1013+24X8100-36+6498-18X5+25456X8:56X812X612X6280 80;26X39+61X26簡便計算練習(xí)題6356X9-56X999X55+5525X8)65+35X13672-36+64324-68+3278X101-7845X13452X76+47X76+76134X56-134+48X52X2-4X4825X23X(40+4)999X999+1999184+98301695+202864-199738-380+476+120(569+468)+(432+131)704X25256-147-53373-129+29189-(8

17、9+74)28X4X25125X32X259X72X125720+16+5簡便計算練習(xí)題7630 42456-(256-36)102X3598X42158+262+138375+219+381+225276+228+353+219(2130+783+270)+1017(375+1034)+(966+125)99+999+9999+999997755(2187+755)2214+638+286創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克/簡便計算練習(xí)題85001-247-1021-232(181+2564)+2719378+44+114+242+2223999+4981883

18、-39812X2575X24138X25X4(13X125)X(3X8)(12+24+80)X503065-738-1065-357899+3442357-183-3172365-1086-214497-2992370+199525X32X125102X76178X101-17875X99+2X7584X36+64X8498X19950X(34X4)X3123X18-123X3+85X12325X(24+16)178X99+17879X42+79+79X577300+25+48100+4+75158+262+1381248+24375+219+381+225簡便計算練習(xí)題931504-1548

19、00 25215004-1255001-247-1021-232(181+2564)+2719378+44+114+242+222276+228+353+219(375+1034)+(966+125)(2130+783+270)+101799+999+9999+999997755-(2187+755)簡便計算練習(xí)題1012X2575X24138X25X4(13X125)X(3X8)32X(25+125)2214+638+2863065-738-1065899+3442357-183-317-3572365-1086-214497-2992370+19953983999+4981883-(12+

20、24+80)X50704X2525X32X12588X125-178102X7658X98178X10184X36+64X8475X99+2X7583X102-83X298X199創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克*(aXb)Xc=aX(bXc)12.5123X18-123X3+85X12350X(34X4)X325X(24+16)178X99+17879X42+79+79X57215004-1257300+25+48100+4+75簡便計算練習(xí)題11(a+b)+c=a+(b+c)168004-1202.73+0.89+1.274.37+0.28+1.63+5.7

21、2a-bc=a(b+c)10一0.432一2.5689.35.262.7414.9-(5.2+4.9)18.32-5.47-4.3225X6.8X0.040.25X32X0.1256.4X1.25XcX(a+b)=cXa+cXb0.45X2010.58X10.150.2X994.7X9.9簡便計算練習(xí)題123.28X5.7+6.72X5.72.1X99+2.1(bXc)930+0.6+563.4+2.5+0.4(7.7+1.54)4-0.7簡便計算練習(xí)題1315.89+(6.75-5.89)7.85+2.34-0.85+4.6635.61.8-15.67.213.75-(3.75+6.48)4

22、7.8-7.45+2.5523X0.1+2.3X9.90.18+4.26-0.18+4.260.58XI.34-0.58XI.37 3+4+2.7X0.253.75X0.52.75 25.26X0.125+2.74+86.3+1.89.54-(1.9X8)12.8-r(0.4XL6)6.9+4.8+3.166.86-8.66-1.340.25X16.2X40.25X32X0.1257755-(2187+755)10652214+638+28630657384.2X9956.5X9.9+56.51.09X10.8一0.8X7.093.83X4.56+3.83X5.443.65X4.736.5X0

23、.375.4X11-5.413.7X0.25-3.74-410.7X16.1-1.1X10.7+10.7X5(181+2564)+2719378+44+114+242+222276+228+353+219(375+1034)+(966+125)(2130+783+270)+101799+999+9999+999992.5X(4+0.4)(1.25-0.125)X84.8X100.1158+262+138232簡便計算專題練習(xí)375+219+381+2255001-247-1021-899+3442142357-183-317-3572365-1086-497-2992370+19953999+

24、4981883-39812x2575x24簡便計算練習(xí)題2138x25x4(13x125)x(3x8)(12+24+80)x50704x2525x32x12532x(25+125)88x125102x7658x98178x101-17884x36+64x8475x99+2x75創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克*50 x(34x4)x325x(24+16)178x99+17816800-120301004.21003200040021500:125簡便計算練習(xí)題32356-(1356-721)1235-(1780-1665)579x42+79+79x5773004

25、.254810034:7549700.r7001248:243150+154800:2583x102-83x298x199123x18-123x3+85x12375x27+19x2(300+6)x12(13+24)x825x(4+8)125x(35+8)84x101504x2578x10225x20499x64999x9999x16638x9999X13+1378X4+78X3+78X325+199X2532X16+14X32125X32X825X32X12588X12572X1253600325:41250:25+5簡便計算練習(xí)題48100M37530003125y1200-624-7621

26、00-728-772273-73-27847-527-27335X127-35X16-11X35簡便計算練習(xí)題5容易出錯類型共五種類型278+463+22+37425+14+186732+580+2681034+780320+102214-(86+14)787-(87-29)365-(65+118)455-(155+230)576-285+85755-287+87825-657+57690-177+77871-299968-599157-99363-199178X101-17883X102-83X217X23-23X7600-604-15736-35X2020X4+20X425X44.25X4

27、98-18X5+2556X8:56X8280-80-r12X64-12X617575+2580-20X2+6025X8:25X836X9:36X936 36:6 6100+45-100+4525X8.15X97+325X8100+1-100+148X99+11000+8-1000+85+95X28102+1-102+165+35X1325+75-25+7540+36020-1013+24X8100-36+64672-36+64324-68+3226X39+61X26簡便計算練習(xí)題6356X9-56X999X55+5578X101-7852X76+47X76+76134X56-134+45X13

28、448X52X2-4X48199925X23X(40+4)999X999+184+98301695+202864-199738-創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克*380+476+120256-147-53(569+468)+(432+131)704X2528X4X25720+16+5102X3598X42373-129+29125X32X25簡便計算練習(xí)題76304-42158+262+1385001-247-1021-232378+44+114+242+222276+228+353+219189-(89+74)9X72X125456-(256-36)375+2

29、19+381+225(181+2564)+2719(375+1034)+(966+125)(2130+783+270)+101799+999+9999+999992214+638+2867755-(2187+755)3065-738-1065317-357899+3442357-183-2365-1086-214497-2992370+19953999+498簡便計算練習(xí)題81883-39812X2575X24138X25X4(13X125)X(3X8)(12+24+80)X5025X32X12532X(25+125)88X125102X76178X101-17884X36+64X8475X9

30、9+2X7598X199123X18-123X3+85X12350X(34X4)X325X(24+16)178X99+17879X42+79+79X577300+25+481004-44-75158+262+138+2719378+44+114+242+222(375+1034)+(966+125)簡便計算練習(xí)題1012X2575X24(13X125)X(3X8)12484-24簡便計算練習(xí)題93150+154800+25215004-125375+219+381+2255001-247-1021-232(181+2564)276+228+353+219(2130+783+270)+10179

31、9+999+9999+999997755-(2187+755)2214+638+2863065-738-1065899+3442357-183-317-3572365-1086-214497-2992370+19953999+4981883-398138X25X4123X18-123X3+85X123(24+16)(12+24+80)X5032X(25+125)704X2525X32X12588X125102X7658X98178X101-17884X36+64X8498X19975X99+2X7583X102-83X2178X99+17879X42+79+79X5721500+1257300

32、+25+4(a+b)+c=a8100+4+75簡 便 計 算 練 習(xí) 題11+(b+c)16800 1202.73+0.89+1.274.37+0.28+1.63+5.72創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克50X(34X4)X325Xa-bc=a(b+c)10-0.432-2.5689.3-5.26-2.74(aXb)Xc=aX25X6.8X804(bXc)0.25X32X0.1256. 4XL25X12.50.58XI.34-0.58XI.37.3+4+2.7X0.253.75X0.52.75+25.26X0.125+2.74+8a+b+c=(bXc)14.9-

33、(5.2+4.9)18.32-5.47-4.32cX(a+b)=cXa+cXb0.45X2010.58X10.150.2X994.7X9.9簡便計算練習(xí)題123.28X5.7+6.72X5.72.1X99+2.123X0.1+2.3X9.90.18+4.26一0.18+4.2695+(L9X8)12.84-(0.4X1.6)35.6-1.8-15.6-7.27. 45+2.5566.86-8.66-1.340.25X16.2X42.5X(4+0.4)(1.25-0.125)X83.83X4.56+3.83X5.445.4X11-5.43.65X4.736.5X0.3710.7X16.1-1.1

34、X10.7+10.7X5930+86+50.76.9+4.8+3.14.6663.4+2.5+0.4簡便計算練習(xí)題1315.89+(6.75-5.89)(7.7+1.54)+7.85+2.34-0.85+4.2X9956.5X9.9+56.57.09X10.8-0.8X7.09第一類：加65+73+135357+288+143272+68+2813.75-75+6.48)47.8-0.25X32X0.1254.8X100.113.7X0.25-3.74-46+7+8+102+103+1049998+3+99+998+3+9第二類：減400-256-44284-159-41545-167-145

35、478-47-178344-(144+37)236 (177+36)88x12572x12542x125x8x5第四類：乘(12+50)x4018x12525x4x88x125125x(40-4)第五類：乘129+235+171+16517+145+23+35999+99+9+3第三類：乘45x4x58x(125x13)23x5x225x9x4(250 x125)x(4x8)25x4442x2599x999x78517-53-47258-42-16125x64x2576x10399x32+3246+46x59(42+25)X125+(18+15)x125167x2+167x3+167x539x

36、8+6x39-39x423x2x4+25x4x2+27x1x8+25x8x199x22+33x34第六類：除360+4+9800+5+8250+5+2600+12+5創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克*480+5X8420 352400+257800X25240+5+12第七類：加減92+99127-98197+102354-108323+189-123248-86+48672-36+6438x46+64x3828x225-2x225-6x225(2+4+6+98+100)-(1+3+5+97+99)2005x20062006-2006x20052005158+2

37、62+138375+219+381+2255001-247-1021-232(181+2564)+2719378+44+114+242+222276+228+353+219(6467-832)+(1832-1467)1530+(592-530)-192第八類：乘除960 x46X899000X21x113702x38+1234640-r(16+4)1000+(125+4)第九類：加減乘除(98+147)v49(230-23)+23(250-25)+251736+28+1064+28125x(860+2404-12)700+612X2x4(37+15)X85+1360(375+1034)+(96

38、6+125)(2130+783+270)+101799+999+9999+999997755-(2187+755)2214+638+2863065-738-1065899+3442357-183-317-3572365-1086-2144972992370+19953999+4981883-39812x2575x24138x25x4(13x125)x(3x8)(12+24+80)x50簡便計算練習(xí)題2704x2588x12525x32x12532x(25+125)102x7658x98178x101-17884x36+64x8475x99+2x75123x3+85x12383x102-83x2

39、98x199123x18一簡便計算練習(xí)題32356(1356-721)531x870+13x310(300+6)x1225x(4+8)4x(25x65+25x28)125x(35+8)(13+24)x884x101504x2578x10225x20499x6499x16638x99999x99299X13+1325+199X2532X16+14X350 x(34x4)x379x42+79+79x5725x(24+16)178x99+1787300+25X0100+21008100*7516800+12032000+400215004-12549700+7001248+243150r548009

40、251235(1780-1665)75x27+19x2871-299157-99363.199968-599簡便計算練習(xí)題5600-604-1520X4+20X4736-35X2025X4+25X478X4+78X3+78X3125簡便計算練習(xí)題43600+25X125X32X88100+4+751200-624-762100-728-77273278+463+22+37732+580+268+18625X32X12588X12572X3000+125+81250+25+5273-73-27847-527-21034+780320+102425+14214-(86+14)787-(87-29)

41、365.(65+118)455-(155+230)576-285+85825-657+57690-177+77755-287+87175.75253636+6612X6X2X625X8+25X880-20X2+6025X8+(25X8)100+45-100+45100+1-100+18102+1-102+11048X99+165+35X131000+8-1000+825+75-25+7513+24X8+64672-36+64324-68+32簡便計算練習(xí)題626x39+61x2678356x956x999x55+5552x76+47x76+76-4x48134x56-134+45x13436X

42、9+36X915X97+35+95X240+360+20,100-3678x101-48x52x2創(chuàng)作編號:BG7531400019813488897SX創(chuàng)別如克,25x23x(40+4)999x999+1999864-199738-301380+476+120(569+468)+(432+131)704x25256-147-53373-129+29簡便計算練習(xí)題7720+16+5630X2456一(256-36)102x3598x42158+262+138375+219+381+2255001-2471021-232(181+2564)+2719378+44+114+242+222276+2

43、28+353+219(375+1034)+(966+125)184+98695+202189-(89+74)28x4x25125x32x259x72x125(2130+783+270)+1017(2187+755)2214+638+28699+999+9999+99999775532x(25+125)88x125102x76178x101-17884x36+64x8475x99+2x7598x199123x18-123x3+85x12350 x(34x4)x3簡便計算練習(xí)題91248+2431509154800+2521500+125375+219+381+2255001-247-1021-2

44、32(181+2564)+27193065-738-1065899+3442357-183-317-3572365-1086-2144972992370+1995簡便計算練習(xí)題83999+4981883-39812x2575x24138x25x45(13x125)x(3x8)(12+24+80)x5025x32x1225x(24+16)178x99+17879x42+79+79x577300+25+48100XK5158+262+138378+44+114+242+222966+125)276+228+353+219(375+1034)+(2130+783+270)+1017(2187+755

45、)99+999+9999+999997755-2214+638+2863065-738-1065899+3442357-183-317-3572365-1086-2144972992370+19953999+4981883-39812x2575x24138x25x4(13x125)x(3x8)(12+24+80)x5025+125)704x2525x32x12532x(88x1258x101-178102x7658x981784x36+64x8475x99+2x7583x298x199(a+b)+c=a+(b+c)2.73+0.89+1.274.37+0.28+L63+5.72abc=a(b+

46、c)10-0.432-2.5689.35.26-2.74(axb)xc=ax(bxc)25x6.8x0.040.25x32x0.12550.2x994.7x9.92.1x99+2.123x0.1+123x18-123x3+85x123(24+16)50 x(34x4)x325x178x99+17879x42+79+79x5721500X257300+25+48100*7516800X2014.9-(5.24-4.9)18.32-5.47-4.3283x102-cx(a+b)=cxa+cxb0.45x2010.58x10.13.28x5.7+6.72x5.76.4xL25x12.52.3x9.9

47、+2.7x0.25a-rb4-c=av(bxc)63v1.89.5T(L9x8)12.8+(0.4x1.6)930-r0.6v563.4+2.5+0.4(7.7+1.54)+0.70.18+4.26-0.18+4.260.58xL3v0.58xl.33.75x0.5-2.75-r25.26x0.125+2.74-r86.9+4.8+3.1+4.6615.89+(6.75-5.89)7.85+2.34-0.8535.61.815.67.27.45+2.5513.75-(3.75+6.48)47.8-66.868.66L342.5x(4+0.4)0.25x16.2x4(1.25-0.125)x80

48、.25x32xO.1254.8x100.14.2x9956.5x9.9+56.57.09x10.80.8x7.0910.7X16.1.L1X10.7+10.7x5倍數(shù)問題11:53:14L甲水池有水2600立方米,乙水池有水1200立方米.如果甲水池里的水以每分鐘23立方米的速度流入乙水池,那么多少分鐘后,乙水池里的水是甲水池的4倍？2.甲水池有42噸水,乙水池有22噸水.現(xiàn)同時從兩個水池中向外排水,排水速度是每分鐘2噸,多少分鐘后,甲水池的水是乙水池的6倍？3.兩個數(shù)的和是16L7,把較大數(shù)的小數(shù)點向左移動一位后就和較小數(shù)相等,這兩個數(shù)各是多少？創(chuàng)作編號:BG7531400019813488

49、897SX創(chuàng)別如克*4.兄弟倆的年齡相差5歲,兄3年后的年齡是弟4年前的3倍,兄弟兩人今年各多少歲？5.某工程甲隊獨做50天可以完成,乙隊獨坐75天可以完成.現(xiàn)在兩隊合做,但是中途乙隊因另有任務(wù)調(diào)走了假設(shè)干天,從開工后40天才把這項工程做完.乙隊中途離開多少天？6.有16位教授,有人帶1名研究生,也有帶2名的,也有帶3名的,他們共帶了27名研究生,其中帶一名研究生的教授人數(shù)和帶2名、3名研究生的教授人數(shù)一樣多,問帶2名研究生的教授有幾人？3.83x4.56+3.83x5.443.7+43.65x4.736.5x0.3713.7x0.255.4x11-5.47、養(yǎng)雞場的母雞只數(shù)是公雞的6倍,后來

50、公雞和母雞各增加60只,結(jié)果母雞的只數(shù)就是公雞的4倍.原來養(yǎng)雞場一共養(yǎng)了多少只雞？8、今年,爸爸的年齡是小明的6倍,再過4年,爸爸的年齡就是小明的4倍.今年小明多少歲？9、原來食堂里存的大米是面粉的4倍,大米和面粉各吃掉80千克,大米的重量是面粉的2倍.食堂里原來存有大米、面粉各多少千克？10、 飼養(yǎng)場的白兔是黑兔的5倍,后來賣掉10只黑兔,買回來20只白兔,現(xiàn)在白兔的只數(shù)是黑兔的7倍.飼養(yǎng)場原來養(yǎng)白兔和黑兔各多少只？11、有1800千克的貨物,分裝在甲乙丙三輛車上.甲車裝的千克數(shù)正好是乙車的2倍,乙車比丙車多裝200千克.甲乙丙三輛車各裝貨物多少千克？12、三堆貨物共1800箱,甲堆的箱數(shù)是

51、乙堆的2倍,乙堆的箱數(shù)比丙堆少200箱,三堆貨物各多少箱？13、甲乙丙三數(shù)的和是224,如果甲是乙的3倍,丙是甲的4倍,求甲乙丙三數(shù)各是多少？14、把840本書放在書架的三層里,下層放的本數(shù)比上層的3倍多5本,中層放的本數(shù)是上層的2倍多1本.問：上中下三層各放書多少本？15、甲乙兩個書架,甲書架有書600本,從甲書架借出三分之一,從乙書架借出四分之三后,甲書架的書是乙書架的2倍還多150本.乙書架原來有書多少本？16、某校有男生630人,選出男生人數(shù)的三分之一和女生的四分之三去排練團體操,剩下的男生人數(shù)是女生人數(shù)的2倍.這個學(xué)校共有學(xué)生多少人？17、食堂存有同樣重量的大米和面粉,吃掉大米的四分之三和60千克的面粉后,剩下的面粉的重量是大米的3倍.原來存有大米和面粉各有多少千克？18、有兩堆水泥,甲堆有4.5噸,甲堆重量的三分之一和乙堆重量的四分之一相等,乙堆有水泥多少噸？19、A站有公共汽車26輛,B站有公共汽車30輛.每小時由A站向B站開出汽車12輛,B站向A站開出汽車8輛,都是經(jīng)過1小時到達.幾小時后B站的公共汽車輛數(shù)是A站的3倍？思路：每小時由A站向B站開出汽車12輛,B站向A站開出汽車8輛,實際上就是每隔1小時,A站就減少4輛,而B站就增加4輛