1、运算定律练习题运算定律练习题.(1 1)乘法交换律:乘法交换律:a ab bb ba a乘法结合律乘法结合律:(a ab b)c ca a(b bc c)3825442125825174(25125)(84)49453812583(12525)45 2892(12512)8125(124)(2)(2)乘法交换律和结合律的变化练习乘法交换律和结合律的变化练习12564125884425125242528(3 3)加法交换律:)加法交换律:a ab bb ba a加法结合律加法结合律:(a ab b)c ca a(b bc c)35728814315839510516728933129235171
2、1653785277316978225839426113829362107(4 4)乘法分配律)乘法分配律:(a ab b)c ca ac cb bc c正用练习正用练习(804)25(204)25(12517)825(404)15(203)(5 5)乘法分配律正用的变化练习:)乘法分配律正用的变化练习:3632541391011258820124(6 6)乘法分配律反用的练习:乘法分配律反用的练习:347234283537653785828518259725376252524(7 7)乘法分配律反用的变化练习:乘法分配律反用的变化练习:3829387529975641996435686868
3、64思考题思考题:(8 8)其他的一些简便运算)其他的一些简便运算.80025600012536008558101 1587499【思路导航】在除法里,被除数和除数同时乘或除以一个相同的数,商不变【思路导航】在除法里,被除数和除数同时乘或除以一个相同的数,商不变.32525=(3254)(254)=1300100=13【练一练【练一练 1】(1)45025(2)52525(3)3500125(4)10000625(5)49500900(6)9000225【经典例题二】计算【经典例题二】计算 2512548【思路导航】如果先把【思路导航】如果先把 25 与与 4 相乘,可以得到相乘,可以得到 1
4、00,同时把,同时把 125 与与 8 相乘,可以得到相乘,可以得到 1000;再把再把 100 和和 1000 相乘就可以了相乘就可以了.运用了乘法交换律和结合律运用了乘法交换律和结合律.2512548=(254)(1258)=1001000=100000【练一练【练一练 2】(1)1251584(2)2524(3)12516(4)7516(5)1252532(6)25564125【经典例题三】计算【经典例题三】计算:(1)12534+12566(2)4311+4336+4352+43【思路导航】利用乘法分配律来计算这两题【思路导航】利用乘法分配律来计算这两题(1)12534+12566(2
5、)4311+4336+4352+43=125(34+66)=43(11+36+52+1)=125100=43100=12500=4300【练一练【练一练 3】计算下面各题:】计算下面各题:(1)12564+12536(2)6445+6471-6416(3)2173+2621+21【经典例题四】计算(【经典例题四】计算(1)(360+108)36(2)12+32+52+72【思路导航】两个数的和、差除以一个数,可以用这个数分别去除这两个数,再求出两个商【思路导航】两个数的和、差除以一个数,可以用这个数分别去除这两个数,再求出两个商的和(差)的和(差).利用这一性质,可以使计算简便利用这一性质,可
6、以使计算简便.(1)(360+108)36(2)12+32+52+72=36036+10836=(1+3+5+7)2=10+3=162=13=8【练一练【练一练 4】(1)(720+96)24(2)(4500-90)45(3)634221(4)881189(5)7336+10536+14636(6)(10000-1000-100-10)10【经典例题五】【经典例题五】15861793【思路导航】在乘除混合运算中,如果算式中没有括号,计算式可以根据运算定律和性质调【思路导航】在乘除混合运算中,如果算式中没有括号,计算式可以根据运算定律和性质调换乘数或者除数的位置,只要计算:数字跟着前面的符号一起
7、移动换乘数或者除数的位置,只要计算:数字跟着前面的符号一起移动.15861793=15879613=2613=366【练一练【练一练 5】计算下面各题:】计算下面各题:(1)238361195(2)138276950(3)624483128(4)406312104203【经典例题六】计算下面各题:【经典例题六】计算下面各题:(1)1039616(2)200(254)【思路导航】这两道题都是乘除法混合运算,我们可以根据这两道题的特点,采用加括号和【思路导航】这两道题都是乘除法混合运算,我们可以根据这两道题的特点,采用加括号和去括号的方法去括号的方法,使计算简便使计算简便.可以概括为可以概括为:括
8、号前是乘号括号前是乘号,加加、去括号不改号去括号不改号,括号前是除号括号前是除号,田、去括号要改号田、去括号要改号.(1)1039616(2)200(254)=103(9616)=200254=1036=84=618=32【练一练【练一练 6】计算下面各题:】计算下面各题:(1)612366183(2)1000(1254)(3)(13856)(456)(4)241345678345(678241)【经典例题七】计算【经典例题七】计算:(1)6862(2)8585【思路导航】这两题的形式叫做【思路导航】这两题的形式叫做“头同尾合十头同尾合十”它们的计算方法是:先用两个因数的个位数相它们的计算方法
9、是:先用两个因数的个位数相乘,并把积直接写在末尾,如果积不满乘,并把积直接写在末尾,如果积不满 10,十位上要补写,十位上要补写 0,然后再将两个因数的十位数乘,然后再将两个因数的十位数乘它本身加它本身加 1 的和,积写在两个个位数积的前面的和,积写在两个个位数积的前面.(1)6862第一步第一步 82=16,第二步,第二步 6(6+1)=42,合起来是,合起来是 4216(2)8585第一步第一步 55=25,第二步是,第二步是 8(8+1)=72,合起来是,合起来是 7225【练一练【练一练 7】(1)2327(2)4644(3)5555(4)9199【经典例题八】计算:【经典例题八】计算
10、:2611【思路导航】一个两位数乘【思路导航】一个两位数乘 11 的方法是:用两位数的头作积的头,用两位数的尾作积的尾的方法是:用两位数的头作积的头,用两位数的尾作积的尾,用这个两位数的两个数字之和作积的中间数(如果相加满十,则把和的十位数用这个两位数的两个数字之和作积的中间数(如果相加满十,则把和的十位数“1”加到头上加到头上.2611第一步第一步 2 作积的头,第二步作积的头,第二步 6 作积的尾,第三步作积的尾,第三步 2+6=8 作中间,合起来是作中间,合起来是 286.【练一练【练一练 8】计算计算(1)5311(2)3911(3)6511(4)9811【经典例题九】计算:【经典例题
11、九】计算:35811【思路导航【思路导航】三位数乘三位数乘 11,用三位数的头作积的头用三位数的头作积的头,用三位数的尾作积的尾用三位数的尾作积的尾,用三位数前两用三位数前两位数字组成的数加厚两位数字组成的数的和作积的中间数位数字组成的数加厚两位数字组成的数的和作积的中间数.35811,第一步用,第一步用 3 作积的头,第二步用作积的头,第二步用 8 作积的尾,在用作积的尾,在用 35+58=93,合起来是,合起来是 3938.【练一练【练一练 9】计算(计算(1)35311(2)65411(3)89611【练一练【练一练 1】(1)45025(2)52525(3)3500125(4)1000
12、0625(5)49500900(6)9000225【练一练【练一练 2】(1)1251584(2)2524(3)12516(4)7516(5)1252532(6)25564125【练一练【练一练 3】计算下面各题:】计算下面各题:(1)12564+12536(2)6445+6471-6416(3)2173+2621+21【练一练【练一练 4】(1)(720+96)24(2)(4500-90)45(3)634221(4)881189(5)7336+10536+14636(6)(10000-1000-100-10)10【练一练【练一练 5】计算下面各题:】计算下面各题:(1)238361195(2
13、)138276950(3)624483128(4)406312104203【练一练【练一练 6】计算下面各题:】计算下面各题:(1)612366183(2)1000(1254)(3)(13856)(456)(4)241345678345(678241)【练一练【练一练 7】(1)2327(2)4644(3)5555(4)9199【练一练【练一练 8】计算】计算(1)5311(2)3911(3)6511(4)9811【练一练【练一练 9】计算】计算(1)35311(2)65411(3)89611简便计算专题训练简便计算专题训练158+262+138375+219+381+225500124710
14、21232(181+2564)+2719378+44+114+242+222276+228+353+219(375+1034)+(966+125)(2130+783+270)+101799+999+9999+999997755(2187+755)2214+638+28630657381065899+3442357183317357236510862144972992370+19953999+498188339812257524138254(13125)(38)(12+24+80)50简便计算练习题简便计算练习题 270425253212532(25+125)881251027658981781
15、011788436+64847599+2758310283298199123181233+8512350(344)325(24+16)17899+1787942+79+79577300254810047516800120301002100320004002150012549700700124824315015480025简便计算练习题简便计算练习题 32356(1356721)1235(17801665)7527+192 531870+133104(2565+2528)(300+6)x1225x(4+8)125x(35+8)(13+24)x884x101504x2578x10225x20499
16、x6499x16638x99999x9999X13+1325+199X2532X16+14X3278X4+78X3+78X3125X32X825X32X12588X12572X125简便计算练习题简便计算练习题 4360025481004753000125812502551200-624-762100-728-772273-73-27847-527-273278+463+22+37732+580+2681034+780320+102425+14+186214-(86+14)787-(87-29)365-(65+118)455-(155+230)576-285+85825-657+57690-1
17、77+77755-287+87871-299157-99363-199968-599178X101-17883X102-83X217X23-23X735X127-35X16-11X35简便计算练习题简便计算练习题 5容易出错类型(共五种类型)容易出错类型(共五种类型)600-601520X420X4736-35X2025X425X498-18X5+2556X856X8280-80 412X612X6175-752525X825X880-20X2+6036X936X936-366-625X8(25X8)100+45-100+4515X97+3100+1-100+148X99+11000+8-10
18、00+85+95X28102+1-102+165+35X1325+75-25+7540+36020-1013+24X8672-36+64324-68+32100-36+64简便计算练习题简便计算练习题 626263939616126263563569 956569 9999955555555787810110178785252767647477676767613413456561341344545134134484852522 24 4484825252323(40404 4)99999999999919991999184184989869569520220286486419919973873
19、8301301380380476476120120(569569468468)()(432432131131)704704252525625614714753533733731291292929189189(89897474)28284 42525125125323225259 97272125125简便计算练习题简便计算练习题 772072016165 56306304242456456(2562563636)1021023535 98984242158+262+138158+262+138375+219+381+225375+219+381+225500150012472471021102
20、1232232(181+2564181+2564)+2719+2719378+44+114+242+222378+44+114+242+222276+228+353+219276+228+353+219(375+1034)+(966+125)(375+1034)+(966+125)(2130+783+270)+1017(2130+783+270)+101799+999+9999+9999999+999+9999+9999977557755(2187+755)(2187+755)2214+638+2862214+638+2863065306573873810651065899+344899+34
21、42357235718318331731735735723652365108610862142144974972992992370+19952370+1995简便计算练习题简便计算练习题 83999+4983999+49818831883398398121225257575242413813825254 4(13(13125)125)(3(38)8)(12+24+80)(12+24+80)5050252532321251253232(25+125)(25+125)88881251251021027676178178101101178178848436+6436+648484757599+299
22、+27575989819919912312318181231233+853+851231235050(34(344)4)3 32525(24+1624+16)17817899+17899+178797942+79+7942+79+7957577300730025254 4810081004 47575158+262+138158+262+138简便计算练习题简便计算练习题 91248124824243150315015154800480025252150021500125125375+219+381+225375+219+381+2255001500124724710211021232232(
23、181+2564181+2564)+2719+2719378+44+114+242+222378+44+114+242+222276+228+353+219276+228+353+219(375+1034)+(966+125)(375+1034)+(966+125)(2130+783+270)+1017(2130+783+270)+101799+999+9999+9999999+999+9999+9999977557755(2187+755)(2187+755)2214+638+2862214+638+2863065306573873810651065899+344899+3442357235
24、718318331731735735723652365108610862142144974972992992370+19952370+19953999+4983999+49818831883398398简便计算练习题简便计算练习题 10121225257575242413813825254 4(13(13125)125)(3(38)8)(12+24+80)(12+24+80)50507047042525252532321251253232(25+125)(25+125)8888125125102102767658589898178178101101178178848436+6436+64848
25、4757599+299+27575838310210283832 2989819919912312318181231233+853+851231235050(34(344)4)3 32525(24+1624+16)17817899+17899+178797942+79+7942+79+79575721500215001251257300730025254 4810081004 475751680016800120120简便计算练习题简便计算练习题 11(a ab b)c c=a a(b bc)c)2.732.73 0.890.89 1.271.274.374.37 0.280.28 1.631
26、.63 5.725.72a ab bc c=a a(b bc c)1010 0.4320.432 2.5682.5689.39.3 5.265.26 2.742.7414.914.9(5.25.24.94.9)18.3218.32 5.475.47 4.324.32(a a b b)c c=a a(b b c c)2525 6.86.8 0.040.040.250.25 3232 0.1250.1256.46.4 1.251.25 12.512.5c c(a+ba+b)=c ca a c cb b0.450.45 2012010.580.58 10.110.150.250.2 99994.74
27、.7 9.99.9简便计算练习题简便计算练习题 123.283.28 5.75.7 6.726.72 5.75.72.12.1 9999 2.12.12323 0.10.1 2.32.3 9.99.90.180.18 4.264.26 0.180.18 4.264.260.580.58 1.31.3 0.580.58 1.31.37.37.3 4 4 2.72.7 0.250.253.753.75 0.50.5 2.752.75 2 25.265.26 0.1250.125 2.742.74 8 8a a b b c c=a a (b b c c)6.36.3 1.81.89.59.5(1.9
28、1.9 8 8)12.812.8 (0.40.4 1.61.6)930930 0.60.6 5 563.463.4 2.52.5 0.40.4(7.77.7 1.541.54)0.70.7简便计算练习题简便计算练习题 136.96.94.84.83.13.115.8915.89(6.75(6.755.89)5.89)7.857.852.342.340.850.854.664.6635.635.61.81.815.615.67.27.213.7513.75(3.75(3.756.48)6.48)47.847.87.45+2.557.45+2.5566.8666.868.668.661.341.3
29、40.250.2516.216.24 40.250.253232 0.1250.1252 2.5.5(4(4+0.4)+0.4)(1.25(1.250.125)0.125)8 84.84.8100.1100.14.24.2999956.556.59.99.956.556.57.097.0910.810.80.80.87.097.093.833.834.564.563.833.835.445.443.653.654.74.736.536.50.370.375.45.411-5.411-5.413.713.70.250.253.73.74 410.710.716.1-1.116.1-1.110.7
30、10.7+10.7+10.7 5 5简便计算专题训练简便计算专题训练158+262+138375+219+381+22550012471021232(181+2564)+2719378+44+114+242+222276+228+353+219(375+1034)+(966+125)(2130+783+270)+101799+999+9999+999997755(2187+755)2214+638+28630657381065899+3442357183317357236510862144972992370+19953999+498188339812257524138254(13125)(38
31、)(12+24+80)50简便计算练习题简便计算练习题 270425253212532(25+125)881251027658981781011788436+64847599+2758310283298199123181233+8512350(344)325(24+16)17899+1787942+79+79577300254810047516800120301002100320004002150012549700700124824315015480025简便计算练习题简便计算练习题 32356(1356721)1235(17801665)7527+192 531870+133104(2565
32、+2528)(300+6)x1225x(4+8)125x(35+8)(13+24)x884x101504x2578x10225x20499x6499x16638x99999x9999X13+1325+199X2532X16+14X3278X4+78X3+78X3125X32X825X32X12588X12572X125简便计算练习题简便计算练习题 4360025481004753000125812502551200-624-762100-728-772273-73-27847-527-273278+463+22+37732+580+2681034+780320+102425+14+186214
33、-(86+14)787-(87-29)365-(65+118)455-(155+230)576-285+85825-657+57690-177+77755-287+87871-299157-99363-199968-599178X101-17883X102-83X217X23-23X735X127-35X16-11X35简便计算练习题简便计算练习题 5容易出错类型(共五种类型)容易出错类型(共五种类型)600-601520X420X4736-35X2025X425X498-18X5+2556X856X8280-80 412X612X6175-752525X825X880-20X2+6036X9
34、36X936-366-625X8(25X8)100+45-100+4515X97+3100+1-100+148X99+11000+8-1000+85+95X28102+1-102+165+35X1325+75-25+7540+36020-1013+24X8672-36+64324-68+32100-36+64简便计算练习题简便计算练习题 626263939616126263563569 956569 9999955555555787810110178785252767647477676767613413456561341344545134134484852522 24 448482525232
35、3(40404 4)999999999999199919991841849898695695202202864864199199738738301301380380476476120120(569569468468)()(432432131131)704704252525625614714753533733731291292929189189(89897474)28284 42525125125323225259 97272125125简便计算练习题简便计算练习题 772072016165 56306304242456456(2562563636)1021023535 98984242158+
36、262+138158+262+138375+219+381+225375+219+381+2255001500124724710211021232232(181+2564181+2564)+2719+2719378+44+114+242+222378+44+114+242+222276+228+353+219276+228+353+219(375+1034)+(966+125)(375+1034)+(966+125)(2130+783+270)+1017(2130+783+270)+101799+999+9999+9999999+999+9999+9999977557755(2187+755)
37、(2187+755)2214+638+2862214+638+2863065306573873810651065899+344899+3442357235718318331731735735723652365108610862142144974972992992370+19952370+1995简便计算练习题简便计算练习题 83999+4983999+49818831883398398121225257575242413813825254 4(13(13125)125)(3(38)8)(12+24+80)(12+24+80)5050252532321251253232(25+125)(25+1
38、25)88881251251021027676178178101101178178848436+6436+648484757599+299+27575989819919912312318181231233+853+851231235050(34(344)4)3 32525(24+1624+16)17817899+17899+178797942+79+7942+79+7957577300730025254 4810081004 47575158+262+138158+262+138简便计算练习题简便计算练习题 9124812482424315031501515480048002525215002
39、1500125125375+219+381+225375+219+381+2255001500124724710211021232232(181+2564181+2564)+2719+2719378+44+114+242+222378+44+114+242+222276+228+353+219276+228+353+219(375+1034)+(966+125)(375+1034)+(966+125)(2130+783+270)+1017(2130+783+270)+101799+999+9999+9999999+999+9999+9999977557755(2187+755)(2187+75
40、5)2214+638+2862214+638+2863065306573873810651065899+344899+3442357235718318331731735735723652365108610862142144974972992992370+19952370+19953999+4983999+49818831883398398简便计算练习题简便计算练习题 10121225257575242413813825254 4(13(13125)125)(3(38)8)(12+24+80)(12+24+80)50507047042525252532321251253232(25+125)(2
41、5+125)8888125125102102767658589898178178101101178178848436+6436+648484757599+299+27575838310210283832 2989819919912312318181231233+853+851231235050(34(344)4)3 32525(24+1624+16)17817899+17899+178797942+79+7942+79+79575721500215001251257300730025254 4810081004 475751680016800120120简便计算练习题简便计算练习题 11(a
42、ab b)c c=a a(b bc)c)2.732.73 0.890.89 1.271.274.374.37 0.280.28 1.631.63 5.725.72a ab bc c=a a(b bc c)1010 0.4320.432 2.5682.5689.39.3 5.265.26 2.742.7414.914.9(5.25.24.94.9)18.3218.32 5.475.47 4.324.32(a a b b)c c=a a(b b c c)2525 6.86.8 0.040.040.250.25 3232 0.1250.1256.46.4 1.251.25 12.512.5c c(a
43、+ba+b)=c ca a c cb b0.450.45 2012010.580.58 10.110.150.250.2 99994.74.7 9.99.9简便计算练习题简便计算练习题 123.283.28 5.75.7 6.726.72 5.75.72.12.1 9999 2.12.12323 0.10.1 2.32.3 9.99.90.180.18 4.264.26 0.180.18 4.264.260.580.58 1.31.3 0.580.58 1.31.37.37.3 4 4 2.72.7 0.250.253.753.75 0.50.5 2.752.75 2 25.265.26 0.
44、1250.125 2.742.74 8 8a a b b c c=a a (b b c c)6.36.3 1.81.89.59.5(1.91.9 8 8)12.812.8 (0.40.4 1.61.6)930930 0.60.6 5 563.463.4 2.52.5 0.40.4(7.77.7 1.541.54)0.70.7简便计算练习题简便计算练习题 136.96.94.84.83.13.115.8915.89(6.75(6.755.89)5.89)7.857.852.342.340.850.854.664.6635.635.61.81.815.615.67.27.213.7513.75(3
45、.75(3.756.48)6.48)47.847.87.45+2.557.45+2.5566.8666.868.668.661.341.340.250.2516.216.24 40.250.253232 0.1250.1252 2.5.5(4(4+0.4)+0.4)(1.25(1.250.125)0.125)8 84.84.8100.1100.14.24.2999956.556.59.99.956.556.57.097.0910.810.80.80.87.097.093.833.834.564.563.833.835.445.443.653.654.74.736.536.50.370.375.
46、45.411-5.411-5.413.713.70.250.253.73.74 410.710.716.1-1.116.1-1.110.710.7+10.7+10.7 5 5第一类:加第一类:加65+73+135357+288+143272+68+28129+235+171+16517+145+23+35999+99+9+36+7+8+102+103+1049998+3+99+998+3+9第二类:减第二类:减400-256-44517-53-47284-159-41258-42-16545-167-145478-47-178344-(144+37)236-(177+36)第三类:乘第三类:乘
47、454523 5225948(12513)(250125)(48)88125721251256425421258525488125第四类:乘第四类:乘(12+50)40125(40-4)7610318125254442259999978第五类:乘第五类:乘4537+37552821+28791723-2373846+64389932+3246+46591672+1673+1675398+639-39428225-2225-6225(42+25)125+(18+15)1252324+2542+2718+25819922+3334第六类:除第六类:除360492505260012580058480
48、548240512420352400257800125第七类:加减第七类:加减92+99197+102354-108127-98323+189-123248-86+48672-36+64(6467-832)+(1832-1467)1530+(592-530)-192(2+4+6+98+100)-(1+3+5+97+99)第八类:乘除第八类:乘除960464899000121113702381234640(164)1000(1254)第九类:加减乘除第九类:加减乘除(98+147)49(230-23)23(250-25)25173628+106428125(860+24012)700+61212
49、4(37+15)85+1360200520062006-200620052005158+262+138375+219+381+22550012471021232(181+2564)+2719378+44+114+242+222276+228+353+219(375+1034)+(966+125)(2130+783+270)+101799+999+9999+999997755(2187+755)2214+638+28630657381065899+3442357183317357236510862144972992370+19953999+498188339812257524138254(131
50、25)(38)(12+24+80)50简便计算练习题简便计算练习题 270425253212532(25+125)881251027658981781011788436+64847599+2758310283298199123181233+8512350(344)325(24+16)17899+1787942+79+795773002548100475168001203 01002100320004002150012549700700124824315015480025简便计算练习题简便计算练习题 32356(1356721)1235(17801665)7527+192 531870+1331