小數(shù)四則混合運(yùn)算專項(xiàng)練習(xí)276題(有答案)ok

1、小數(shù)混合運(yùn)算專項(xiàng)練習(xí) 276題（有答案）(1)0.11 X1.8+8.2 X0.11(9 )1.8 X (3.41 2.9) +0.03(2)2.34X99+2.34(10 )0.125X32X2.5.(3 )5.4+2.7X0.8(11)1.258 X18.5- 0.258 X18.5(4 )132 X101(12 )8.48+0.8X0.9(5 )6.25+1.25 F.8(13 )1.25X2.4(6 )2.5X16.(14 )5.85+ (1.3+0.5) X6.(7 )6.33X101 - 6.33(15)17.17 - 6.8- 3.2 - 6.17(8)1.56 X1.7+0.4

2、4 X1.7(16)5.4 X (1.3+2.15 ) +0.2(17)8.4F.6+8.4 F.4(25 )83.7 12.83 0.17(18)16.8X10.1(26 )5.96+13 X (3.2 3.12)(27 )4.32+2.4X1.7;(19)10.9-0.90.2+1.8(20)1.25X3.2X0.25.(21)1.36+4.85+2.64+6.15(29 )9.05 3.86 3.14;(28)16.2X4.5+3.8 X4.5;(22)98.5+2.5+4(30 )7.28+0.72 F.9(23)5.4Y2.5X (3.72.9)(31)4.32+5.43+6.68(

3、32 )17.17 6.8- 3.2(24)0.8X (4 3.68) +0.01(33)5.29X9+5.29(41)15.68 - ( 7.78 4.32) - 2.32(40)1.25X32X0.25.(48 )25X11.2X4(34)16.8X10.1(42 )0.25X3.2X1.25(43 )9.99X1.01(35)2.74X9.5+5 X0.274(36)0.36+9.6 +3.2.(44 )4.63X1.4+46.3 X0.86(45 )17.5+0.8+12.5(37) 3.75X25+6.25 X25(38) 25.46 8.23- 1.76(46 )0.9+9.9+9

4、9.9+999.9(47 )2.9X99+2.9(39) 2.9+7.1 X10(49)23.25 6.75- 3.25.(57 )35.6- 5X1.73(50)125 X3.2X2.5(58 )1.6X55.4 55.4X0.6(51)3.6X10.1(59 )17.68 抬.2+2.7 X1.5.(52)5.8X2.7+0.58 X73(60 )1.08X0.8+0.27(53)3.6+6.4X1.8(61)102 X0.45(54)(1.48+3.02 ) + (3.6X0.5)(62 )22.78+1.25+0.8(55)(36.7 4.9) X101 31.8.(63)0.34X1

5、01 0.34.(56)6.33 X101 6.33(64)0.125X32X2.5(65)0.8X6.3 0.8X3.8(73 )10.8-0.8- (0.35+0.05 )(66)504+3.2X2.08(74 )8X1 + (2.32.25 )(75 )2.64 X9.9+0.264(67) (20 0.8X9) X5.7(68) 2.4X1.5+3.6 +1.5(76 )4.52+0.61+1.39+6.48(69) 7.38- 5.14+3.62 2.86(77 )4.27- ( 1.96 1.73 )(70)0.12X1.8+8.2 X0.12(78 )(294.4 - 19.2X

6、6) + (6+8)(71) 5.40.51 + (1.21.03)(79 )12.5X0.76X0.4X8X2.5.(80)4.98+8.02 X2.5(72) (8.15.6) X0.9- 1.05p0.04.(81)60.8 40.8+2.5(89 )7.2360.18- 14.3X0.02.(82)0.8X69.6X12.5(90 )9.6+0.4X0.25(83)4.98X99+4.9(91)29.7 + (5.85+0.65 )(92 )7.4X9.9(84) 6.48+3.2+2.5(85) 1.2X7.6+7.6 X6.8.(93 )3.84- 2.7X0.64(86) (9.

7、4 5.8) X2.07(94 )8.68 8.68+0.56X0.5(87) 12.54 4.56 3.44 1.54(95)4.7X4.7+4.7+4.3 X4.7.(96)2.72+ (8.2 6.5) X0.5;(88) (9.36 X5+9.36+9.36 X2) X1.25(97)9.12+9.12 X9 60.2;(105) 11.87 - ( 8.2+1.87 )(98)28.40.4-0.25;(106) 5.42 3.87 1.13(99)27.36 27.36+7.6.(107) 4.38- 1.56+0.62 0.44(100)3.25X0.45+6.75 X0.45(

8、108) 0.4X270X2.(101) 31.5 24.5+3.5(109)(40+1.25 ) X8(102) 7.5X102(110)(12.5 0.05) X8(103) 6.3+3.7X2.8.(111 ) 2.6X8.5+8.5 X7.4(104) 2.15+8.73+1.27+7.85(112) 9.9X6.9- 6.9X3.9(113) 5.6X99+5.6(121 ) 0.25X1.25X3.2(122) 6.4X14+15 X6.4+6.4(114) 2.5X (1.9+1.9+1.9+1.9 )(115)7.2+1.25+8.(116) 52.4- ( 15+0.6 )

9、+1.6(124) 4X (25+2.5+0.25 )+111(123)(1.3+1.3 X0.125 X8) + (80 77.4 )(117) 9.87X99+9.87(125) 6.25+(17.23.6X4.5) +0.32(118) 46.80.9-0.4(126) 28.4X99+28.4(119) 5.5X17.3+6.7 X5.5.(127) 0.94X2.5- 0.45(120) 99X4.2+4.2(128) 4X0.8X12.5X2.5(129) 17.5F.25X17+13 .(137) 7.5 ( 5.5+1.24 )(130) 10.1 X87(138) 0.26+

10、15.68+9.74+2.32(139) 13.26+9.55 3.26(131) 2.3+3.19 + (22 - 19.8)(132)1.25X7.2.(140) 6.1+3.9 6.1+3.9 .(133) 9.1 1.2+6 6.24(141) 31.7+0.63 (保留 2 位小數(shù))(134) 7.3+12.8 3.8X2.3(142) 2.4X1.5+3.6 +1.5(143) 0.32 X0.25+0.08 +4(135) (5.36+7.64 ) +13X100(144)(9.6+1.48 +3.7) +8(136) 7.575(5.63- 1.88) X0.2.(145) 5

11、.8丑4>< (1.34 0.14)(153)(45+14 ) +73+710 .(154)13.7X0.125X8(147)21.35 3.25 16.75(155)0.8X13 ( 3.12+5.28 )(148)33.02 - ( 148.4 90.85) +2.5(156)102 X0.56(149)32X2.5X0.125(157)1.53X1.7+0.47 X1.7.(150) 18.1+ (3 0.299+0.23) X1 .(158)5.18+0.73+0.82(151) 67- ( 2.98+0.67 )(159)0.75X1.8+1.5(152) 8X16 73

12、.8X6(160)12.5X7.1 X0.8(146) 5.40.51 + (1.21.03).(161)6.12X99+6.12(169)12.7+12.5+0.5 .(170)91 +2.6+0.05=(162) 8.60.86+8 X0.35(163) 5.6X (18.58.5+0.5)(171)6.3X3.7+6.3 X6.3=(164)0.125X4.78X80(172)(3.7+1.7 X0.4) +2.5=(165)2.8X3.6+1.4 X2.8(173)7.28+3.2 +2.5=(166)(0.4+40 ) X2.5(174)0.74+0.9 X7.4=(167)78.7

13、- 17.7X3.6(175)7.8-0.1250.8=(168)18-0.3X (86.5)(176)37.5 +0.3 X (1.34 0.84)(177)(2.5+27.75 +1.5) X1.6.(185)64 X4.5+3.6 X45(178)6.21 3.8+2.2(186)1.25X3.2X0.8(179)6.03+3.7+2.97(187)14.5X102(180)17.43 6.57 - 2.43(188)14.64+3.7 X2.8(181)20.47 - ( 1.47+6.8 )(189)8.4+0.21 +0.5.(182)13.26+4.71+3.47+5.29(18

14、3)22.74+8.68 13.74.(190)0.125X9X8X0.3(184)10+0.2+2.5(191)4.62+5+0.66(192)5.78X2.3+5.78+5.78 X6.7(200)18.2T0.6X (0.90.75)(201)0.25X3.85X40(194)1.25X0.5X8X0.2(202)1.46 X3.5+3.5 X4.54.(193)7.75X20 + (3.24 3.04).(199)32.4X6.3+32.4 X3.7(207)15.02 - 6.8- ( 1.02+1.2 )(203)7X12.5X0.8(195) 0.97X9+0.97(204)4.

15、7X3.6+4.7 X6.4(196) 5.4 Y3X (3.8- 2.9).(197) 0.4 X (3.2 0.8) +0.15(205) 1.45X (2.8+4.4) +2.4.(198)5.7+1.9 X0.2+7.6(206) 4.2X (6.18 - 3.03) +6.3(208)0.6X (50.68) +1.2(216)2.7X1.5- 2.7(209)2.7X+6.3 X0.25(217)9.08+5.45+11.92+4.55(210)(6.02+2.8 ) +0.42.05(218)1.25X30X1.2X0.8.(211)3.08X3.5+6.2 X3.08+3.08

16、 X0.3.(219)0.6+0.94 0.208(212)2.3+3.91 + (22 19.7)(220)4.85X1.25X8(213)21.664.8 - ( 48.6- 2.7X2).(221)(64- 22.4+1.4) X1.2(214)93.6X3.6+1.4 X3.6(222) 18.3- 6.25- 3.75(215)0.25X0.8X0.125 X0.4(223) 2.8X3.6+1.4 X2.8(224)6.6+14.5 ( 1.7+1.8)(232) (7.6 5.2) +0.4+2.54 732 .(225)0.25X9.87X4(233) 17.68 抬.2+2.

17、7 X1.5(226)36.7X2.1+10.8(234)35.6- 5X1.73(227)8.45 0.45X0.1(228) 0.73 X102(237) 1.08+1.8X1.2(238) 50.4X1.9- 1.8(235) (1.1 0.78) X (2.7 1.95)(236) 1.3X0.75X4(229) 7.8X5.6+2.3 X4.4(230) 76.3X27 - 76.3X17.(231) 7.05 X23.7+7.05 X76.3 .(239) 0.82 X0.25+1.18 X0.25.(240)8.5 X (2.36+2.42 ) +0.25(248)8X (20-

18、 1.25)(249)0.654+10.9 X6.5(241) 3.9丑(1.3+0.6) X6-3.6(250)22.7X1.25X0.8(242) 4.25X6.3+3.7 X4.25(243) 205 X0.99(251)3.91 X2.8+6.09 X2.8.(252)6.23+3.09=(244) 25.6- 7.49- 2.51(253)132.4 - 59.8=(245) 2.5 (6.8 4.9) X0.8 .(246)102 X4.5(254)6.62 X0.84=(255) 2.07+0.023=(247)3.4Y (1.2+0.5) X5(256)20.026 - ( 8

19、.6+9.7) X0.92+30.19 .(264)2.5X99+2.5 ;(257)0.125X32X2.5(265)10.36+4.8 16.5+5;(266)12.5X2.4.(258)0.8X6.3 - 0.8X3.8(259) 50.4+3.2X2.08(260) 204 + (3.4X0.5)(261)(43.26+2.34 ) +7.5(269)0.08 X (12.5+2.5 ) X0.1(267) 38.78 - 19.59+41.22 - 30.41(268) 2.74 X4.86+4.86 X6.26+4.86(262)(20 0.8X9) X5.7.(270)25.92

20、+ (10.1 - 14.5X0.2)(271)0.487X12.5+48.7(263)13.25 0.8+1.75 T.2;(272)(8.16+2.09 ) +(10.39.3) +0.4.(275)0.25X2010+20.10 X75(273)1.56 X1.7+0.44 X1.7(276)30.8寸(6.34 4.59) X4.(274)12.5X (7.2- 1.9) X0.8參考答案(13) 1.25X2.4,(1) 0.11 X1.8+8.2 X0.11 ,=0.11 X (1.8+8.2),=0.11 X10, =1.1 ;(2) 2.34 X99+2.34 ,=2.34 X

21、 (99+1 ),=2.34 X100, =234 ;(3) 5.4+2.7X0.8,=2 X0.8, =1.6 ;(4) 132 X101 ,=132 X (100+1 ),=132 X100+132 , =13332 ;(5) 6.25-1.250.8,=6.25 + (1.25X0.8),=6.25 +1 ,=6.25 ;(6) 2.5X16, =(2.5X4) X4, =40 6.33 X101 - 6.33,=6.33 X (101 - 1),=6.33 X100, =633 ;(8) 1.56 X1.7+0.44 X1.7,=1.7 X (1.56+0.44 ),=1.7 X2,=

22、3.4 ;(9) 1.8X (3.41 - 2.9) +0.03, =1.8 X0.51 F.03, =1.8 X17, =30.6 ;(10) 0.125 X32X2.5, =(0.125X8) X (4X2.5), =1 X10, =10(11) 1.258 X18.5- 0.258 X18.5,=18.5 X (1.258 - 0.258),=18.5 X1 , =18.5 ;(12) 8.48+0.8X0.9,=10.6 X0.9, =9.54 ;=1.25 X8X0.3,=10 X0.3,=3 ；(14) 5.85+ (1.3+0.5) X6, =5.85 +1.8X6, =3.25

23、 X6, =19.5(15) 17.17-6.8-3.2- 6.17=(17.17 - 6.17) - ( 6.8+3.2 ), =11 -10, =1 ；(16) 5.4 X (1.3+2.15 ) +0.2=5.4 X3.45 F.2,=5.4 X17.25 , =93.15 ;(17) 8.4+0.6+8.4 刃.4=14+21=35 ;(18) 16.8X10.1=16.8 X10+16.8 X0.1,=168+1.68 , =169.68 ;(19) 10.9-0.9+0.2+1.8=10.9 - 4.5+1.8 ,=8.2 ;(20) 1.25X3.2X0.25=(1.25X0.8

24、) X (4X0.25),=1 X1 , =1(21) 1.36+4.85+2.64+6.15 ,=(1.36+2.64 ) + (4.85+6.15 ), =4+11 , =15 ;(22) 98.52.5-4,=98.5 + (2.5X4),=98.5 +10,=9.85 ;(23) 5.4 +2.5 X (3.7-2.9), =5.4 Y2.5X0.8, =5.4 +2, =2.7;(24) 0.8X (4- 3.68) +0.01,=0.8 X0.32F.01 ,=0.256 F.01 , =25.6 ;(25) 83.7 - 12.83 - 0.17, =83.7 - ( 12.83

25、+0.17 ), =83.7 - 13, =70.7 ;(26) 5.96+13 X (3.2- 3.12), =5.96+13 X0.08, =5.96+1.04 ,=7 .(27) 4.32+2.4X1.7,=1.8 X1.7,=3.06 ;(28) 16.2X4.5+3.8X4.5,=(16.2+3.8) X4.5,=20 X4.5,=90 ;(29) 9.05- 3.86- 3.14,=9.05 - ( 3.86+3.14 ),=9.05 -7,=2.05 ;(30) 7.28+0.72 -0.9, =7.28+0.8 , =8.08(31) 4.32+5.43+6.68 , =4.3

26、2+6.68+5.43 , =11+5.43 ,=16.43 ;(32) 17.17-6.8-3.2,=17.17 - (6.8+3.2 ),=17.17 - 10,=7.17 ;(33) 5.29X9+5.29,=5.29 X (9+1 ),=5.29 X10,=52.9 ;(34) 16.8X10.1, =16.8 X10+16.8 X0.1, =168+1.68 , =169.68 ;(35) 2.74X9.5+5 X0.274, =2.74 X9.5+0.5 X2.74, =2.74 X (9.5+0.5),=2.74 X10,=27.4 ;(36) 0.36+9.6 -3.2,=0.

27、36+3 ,=3.36(37) 3.75X25+6.25 X25,=25 X (3.75+6.25 ),=25 X10,=250 ;(38) 25.46 - 8.23 - 1.76,=25.46 - ( 8.23+1.76 ),=25.46 - 9.99=15.45 ;(39) 2.9+7.1 X10,=2.9+71 ,=73.9 ;(40) 1.25X32X0.25=(1.25X8) X (4X0.25),=10 X1, =1 .(41) 15.68 - ( 7.78 - 4.32) - 2.32,=15.68 - 7.78+4.32 - 2.32,=(15.68+4.32 ) - ( 7.

28、78+2.32 ),=20 -10,=10 ;(42) 0.25X3.2X1.25,=0.25 X4X0.8X1.25,=(0.25X4) X (0.8X1.25),=1 X1 ,=1 ;(43) 9.99X1.01,=(10-0.01) X1.01 ,=10.1 - 0.0101 ,=10.0899 ;(44) 4.63X1.4+46.3 X0.86,=46.3 X0.14+46.3 X0.86,=46.3 X (0.14+0.86 ),=46.3 X1,=46.3 ;(45) 17.50.8-12.5,=17.5 + (0.8X12.5),=17.5 +1,=17.5 ;(46) 0.9+

29、9.9+99.9+999.9 ,=1 - 0.1+10 - 0.1+100 - 0.1+1000 - 0.1 , =(1+10+100+1000 ) - ( 0.1+0.1+0.1+0.1 ), =1111 - 0.4, =1110.6(47) 2.9X99+2.9=(99+1 ) X2.9,=100 X2.9,=290 ;(48) 25X11.2%=25 X4X11.2,=100 X11.2,=1120 ;(49) 23.25 - 6.75 - 3.25=100 X0.45+2 X0.45=23.25 - ( 6.75+3.25 ),=23.25 - 10,=13.25(50) 125X3.

30、2X2.5,=125 X8X0.4X2.5,=(125X8) X (0.4X2.5),=1000 X1, =1000 ;(51) 3.6X10.1 ,=3.6 x (10+0.1 ),=3.6 X10+3.6 X0.1,=36+0.36 , =36.36 ;(52) 5.8X2.7+0.58 X73,=5.8 X2.7+5.8 X7.3,=5.8 X (2.7+7.3),=5.8 X10, =58 ;(53) 3.6+6.4X1.8,=3.6+11.52 , =15.12 ;(54) ( 1.48+3.02 ) + (3.6X0.5), =4.5 +1.8, =2.5 ;(55) (36.7-

31、 4.9) X101 - 31.8,=31.8 X101 - 31.8,=31.8 X (101 - 1),=31.8 X100, =3180(56) 6.33X101 - 6.33=6.33 X (101 - 1),=6.33 X100, =633 ;(57) 35.6- 5X1.73,=35.6 - 8.65, =26.95 ;(58) 1.6X55.4 -55.4X0.6,=55.4 X (1.6-0.6),=55.4 X1 ,=55.4 ;(59) 17.68.2+2.7X1.5, =3.4+4.05 , =7.45(60) 1.08X0.8F.27=1.08 +0.27X0.8,=4

32、 X0.8,=3.2 ;(61) 102 X0.45 =(100+2 ) X0.45,=45+0.9 ,=45.9 ;(62) 22.78+1.25 刃.8=22.78 + (1.25X0.8),=22.78 +1 ,=22.78 ;(63) 0.34X101 - 0.34=(101 - 1) X0.34,=100 X0.34,=34(64) 0.125X32X2.5,=(0.125X8) X (4X2.5),=1 X10,=10 ;(65) 0.8X6.3- 0.8X3.8,=0.8 X (6.3 - 3.8),=0.8 X2.5,=2 ；(66) 504+3.2X2.08,=157.5 X

33、2.08,=327.6 ;(67) (20 - 0.8X9) X5.7,=(20-7.2) X5.7,=12.8 X5.7,=72.96(68) 2.4X1.5+3.6+1.5,=3.6+2.4 ,=6 ；(69) 7.38 -5.14+3.62 -2.86,=(7.38+3.62 ) - ( 5.14+2.86 ),=11 - 8,=3 ；(70) 0.12X1.8+8.2 X0.12,=0.12 X (1.8+8.2),=0.12 X10,=1.2；(71) 5.4 +0.51 + (1.2 - 1.03),=5.4 丑0.51 F.17,=5.4 +3,=1.8 ;(72) (8.1-5

34、.6) X0.9- 1.05-0.04,=2.5 X0.9- 1.05包04,=2.25 - 1.05-0.04,=1.2 F.04,=30(73) 10.8-0.8- (0.35+0.05 ),=10.8 - 0.8F.4,=10.8 -2,=8.8 ;(74) 8漢1 + (2.3-2.25),=8 X1 F.05,=8 X20, =160 ;(75) 2.64 X9.9+0.264 ,=0.264 X99+0.264 ,=0.264 X (99+1 ),=0.264 X100, =26.4 ;(76) 4.52+0.61+1.39+6.48=(4.52+6.48 ) + (0.61 +

35、1.39 ),=11+2 ,=13;(77) 4.27- ( 1.96- 1.73)=4.27 - 0.23,=4.04 ;(78) (294.4- 19.2X6) + (6+8) =(294.4 - 115.2) +14, =179.2 +14, =12.8 ;(79) 12.5X0.76 X0.4X8X2.5 =(12.5X8) X (0.4X2.5) X0.76, =100 X1X0.76, =76 .(80) 4.98+8.02 X2.5, =4.98+20.25 , =25.03 ;(81) 60.8- 40.8-2.5,=60.8 - 16.32 ,=44.48 ;(82) 0.8

36、X69.6X12.5, =(0.8X12.5) X69.6, =10 X69.6, =696 ;(83) 4.98X99+4.9, =493.02+4.9 , =497.92 ;(84) 6.48+3.2 及.5,=6.48 + (3.2X2.5),=6.48 +8,=0.81 ;(85) 1.2X7.6+7.6 X6.8,=7.6 X (1.2+6.8),=7.6 X8,=60.8(86) (9.4-5.8) >2.07,=3.6 >2.07,=7.452 ;(87) 12.54 -4.56 - 3.44- 1.54,=(12.54 - 1.54) - ( 4.56+3.44 )

37、,=11 - 8,=3 ；(88) (9.36X5+9.36+9.36 X2) M.25, =9.36 X (5+2+1 ) M.25, =9.36 X8M.25, =9.36 X (8M.25), =93.6 ;(89) 7.2360.18- 14.3X0.02,=40.2 - 0.286, =39.914 .(90) 9.6+0.4X0.25,=24 X0.25,=6 ；(91) 29.7 + (5.850.65),=29.7 +9,=3.3 ;(92) 7.4X9.9,=7.4 X (10 - 0.1),=7.4 X10 - 7.4X0.1,=74 - 0.74,=73.26 ;(93)

38、 3.84 -2.7X0.64,=3.84 - 1.728,=2.112 ;(94) 8.68 -8.680.56X0.5,=8.68 - 15.5X0.5,=8.68 - 7.75,=0.93 ;(95) 4.7X4.7+4.7+4.3 X4.7,=4.7 X (4.7+4.3+1 ),=4.7 X10,=47(96) 2.72 胃(8.2-6.5) X0.5=2.72 +1.7X0.5,=2.72 +0.85,=3.2 ;(97) 9.12+9.12 X9- 60.2=(1+9) X9.12- 60.2,=10 X9.12- 60.2,=91.2 - 60.2,=31 ；(98) 28.4

39、0.4-0.25=28.4 + (0.4X0.25),=28.4 +0.1, =284 ;(99) 27.36 - 27.36-7.6(112) 9.9X6.9-6.9X3.9,=27.6 - 3.6, =24(100) 3.25X0.45+6.75 X0.45, =0.45 X (3.25+6.75 ), =0.45 X10, =4.5 ;(101) 31.5-24.5-3.5,=31.5 -7,=24.5 ;(102) 7.5X102,=7.5 X (100+2),=7.5 X100+7.5 X2,=750+15 ,=765 ;(103) 6.3+3.7X2.8, =6.3+10.36 ,

40、 =16.66 .(104) 2.15+8.73+1.27+7.85=(2.15+7.85 ) + (8.73+1.27 ),=10+10 ,=20 ;(105) 11.87 - (8.2+1.87 ), =11.87 - 1.87- 8.2, =10 - 8.2,=1.8 ;(106) 5.42 - 3.87 - 1.13,=5.42 - 5,=0.42 ;(107) 4.38- 1.56+0.62 - 0.44, =(4.38+0.62 ) - ( 1.56+0.44 ), =5 - 2,=3；(108) 0.4X270X2.5,=(0.4X2.5) X270, =270 ;(109) (

41、40+1.25 ) X8,=40 X8+1.25 X8,=320+10 ,=330 ;(110) (12.5-0.05) X8,=12.5 X8 - 0.05X8,=100 - 0.4,=99.6 ;(111) 2.6X8.5+8.5 X7.4, =(2.6+7.4) X8.5, =85 ;=(9.9-3.9) X6.9,=6 X6.9, =41.4 ;(113) 5.6X99+5.6 ,=5.6 X (99+1 ), =560 ;(114) 2.5 X (1.9+1.9+1.9+1.9 ),=2.5 X4X1.9,=10 X1.9, =19 ;(115) 7.2+1.25 咫=7.2 y+1

42、.25,=0.9 +1.25,=0.72 .(116) 52.4- (15+0.6 ) +1.6,=52.4 - 15.6+1.6,=52.4 - 9.75, =42.65 ;(117) 9.87X99+9.87 ,=9.87 X (99+1 ), =987 ;(118) 46.80.90.4,=46.8 + (0.9X0.4),=46.8 +0.36, =130 ;(119) 5.5X17.3+6.7 X5.5,=5.5 X (17.3+6.7),=5.5 X24, =132(120) 99 X4.2+4.2=4.2 X (99+1 ),=4.2 X100, =420 ;(121 ) 0.2

43、5X1.25X3.2=0.25 X1.25X (4X0.8),=0.25 X4X (1.25X0.8),=1 X1 ,=1 ；(122) 6.4X14+15 X6.4+6.4=6.4 X (14+15+1 ),=6.4 X30, =192 ;(123) (1.3+1.3 X0.125X8) + (80 -77.4) =(1.3+1.3 X1) +2.6, =2.6 +2.6, =1 ；(124) 4X (25+2.5+0.25 )+111=(4X25+4 X2.5+4 X0.25) +111,=(100+10+1 ) +111,(137) 7.5 (5.5+1.24 ),=111 +111 ,

44、=1 ；(125) 6.25，(17.2-3.6X4.5) +0.32 =6.25 寸(17.2 - 16.2) +0.32, =6.25 + (1 +0.32),=6.25 +3.125, =2(126) 28.4X99+28.4,=28.4 X (99+1 ),=28.4 X100, =2840 .(127) 0.94X2.5- 0.45,=2.35 - 0.45,=1.9 .(128) 4X0.8X12.5X2.5,=(4X2.5) X (0.8X12.5),=10 X10, =100 .(129) 17.5+0.25X17+13,=70 X17+13 ,=1190+13 , =1203

45、(130) 10.1 X87,=(10+0.1 ) X87,=87+8.7 ,=95.7 ;(131) 2.3+3.19 + (22 - 19.8), =2.3+3.19 +2.2, =2.3+1.45 , =3.75 ;(132) 1.25X7.2,=1.25 X8X0.9,=10 X0.9, =9(133) 9.1 - 1.2 4-6.24=9.1 - 0.2-6.24,=8.9 - 6.24, =2.66 ;(134) 7.3+12.8 - 3.8X2.3=20.1 - 8.74,=11.36 ;(135) (5.36+7.64 ) +13X100=13 +13X100, =100 ;(

46、136) 7.575(5.63 1.88) X0.2=7.575 丑3.75 X0.2,=7.575 F.75, =10.1=7.5 -5.5- 1.24, =2 - 1.24, =0.76 ;(138) 0.26+15.68+9.74+2.32 ,=(0.26+9.74 ) + (15.68+2.32 ),=10+18 ,=28 ;(139) 13.26+9.55 - 3.26,=13.26 - 3.26+9.55 ,=10+9.55 ,=19.55 ;(140) 6.1+3.9 - 6.1+3.9 ,=6.1 -6.1+ (3.9+3.9),=0+7.8 ,=7.8(141) 31.7 刃

47、.63 = 50.32;(142) 2.4X1.5+3.6 +1.5=3.6+2.4 ,=6 ；(143) 0.32X0.25+0.08 F=0.08+0.08 X,=0.08+0.02 ,=0.08+0.02 ,=0.1 ;(144) (9.6+1.48 +3.7) +8=(9.6+0.4) +8,=10 +8,=1.25 ;(145) 5.8 胃4 X (1.34 - 0.14)=5.8 丑4 X1.2,=5.8 -8,= 1.21 ;(146) 5.4 胃0.51 + (1.2 - 1.03)=5.4 丑0.51 F.17,=5.4 +3,=1.8(147) 21.35 - 3.25-

48、16.75 ,=21.35 - ( 3.25+16.75 ),=21.35 - 20,=1.35 ;(148) 33.02 - ( 148.4 - 90.85) +2.5,=33.02 57.55+2.5,=33.02 - 23.02,=10 ;(149) 32X2.5X0.125,=4 X8X2.5X0.125,=(4X2.5) X (8X0.125),+71073=7105973=10 X1 ,=10 ;(150) 18.1+ (3- 0.299+0.23) X1,=18.1+ (3- 1.3) X1,=18.1+1.7 X1,=18.1+1.7 ,=19.8(151) 67 - (2.98+0.67 ), =67 3.65, =63.35 ;(152) 8X16 -73.8X6,=128+442.8 ,=570.8 ;(153) (45+14