1、小數(shù)加減法專項練習(xí)200題（有答案）(1)7.4+12.86(10)12.42+0.48(2)20-5.674(11)0.56+11.534(3)141.2-48.98(12)44-22.13(4)102+4.36(13)91-22.035(5)32.15-27.45(14)52.6+21.237(6)12.9+5.01(15)9.15-2.1829.46(9.46+3.8)(16)3.85-1.5+1.32,(17)15.4+6.87(8)15.75+0.65-2.75+3.35123.56-47.9+51.7(30)57.5-3.2516.75,2.7+3.1+2.9+3.2,(31)6.

2、02+3.6+1.9828.42+19.48(32)1.29+3.7+2.71+6.342.56+3.124(33)3.07-0.381.628130.75(34)3.25+1.79-0.59+1.7515.6十0.237(35)7.5+4.9-6.1(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)148.2-25.6224.38(36)14.8+7.9-4.8(37)2.608+2.844.520.740.26(40)76.8+26.82(50)17.176.8-3.2-6.17(41)102.07-37.257(51)73.8-1.64-13.8-5.36(

3、42)48.64+18.6(52)6.75(0.9+3.75)(43)54.75-5.2514.75,(53) 27.38-5.34+2.62-4.66(44)4.68+14.79+5.32-10.79,(54) 35.72-4.9-(5.72+5.1)(45)48.912.7-0.3,(55) 0.73-0.25-0.73+0.25(46) 56.4-39.7+24.3,(56)5.3+0.1+5.3-0.1(47) 3.62.8+3.47.2,(57) 12.7-4.8-5.2.(48)3.67+18.5+6.33,(58) 23.256.753.25(60)9.05-3.86-3.14(

4、70) 27042.517.5(61)20-9.18-0.82(71) 15.68-(7.784.32)2.32,(62) 6.53(1.53+2.6)(72)0.9+9.9+99.9+999.9,(63) 5.521.0740.926(73)25.468.23-1.76,(74)9.4+0.36.4,(64) 4.21+1.04+0.79(65) 1.36+4.85+2.64+6.15(75) 15.25+4.72+4.75+5.28,(66)83.712.83-0.17(76) 34.823(4.82+15.2),(67)4.32+5.43+6.68(77) 12.7-4.8-5.2,(6

5、8)17.17-6.8-3.2,(78) 3.1+25.78+6.9,(80) 2.15+8.73+1.27+7.85(90)15.17(3.6+4.9),(81) 11.87(8.2+1.87),(91)35.6+(12.6-4.4),(82) 5.42-3.871.13,(92)16.4+3.5+83.6+166.5(93)4.65-2.55-1.45,(83) 4.38-1.56+0.620.44,(84) 46.715.03-4.97(94) 1.28+0.86+38.72,(85)4.52+0.61+1.39+6.48(95) 25.743.576.43,(86)4.27(1.96-

6、1.73)(96) 14.5-4.68-5.32,(87)7.27(1.98+0.27),(97) 0.485+0.64+3.36,(88)13.7+8.65-9.628,(98) 72.519.3412.66,(100)5.76+2.43+0.24+10.57,(110)27.73(4.73-1.85),(101)9.28(3.28+2.55),(111)3.84+26.5(20-8.6),(102)9.5+4.856.13,(112)7.385.14+3.62-2.86,(103)10.75-1.86-2.75-3.16,(113)5.86+13.089.27,(104)1.3+0.94+

7、0.06+7.7,(114)25.4-(15.4-6.4),(105)4.45+0.63+5.55,(115)47.23-7.23-5.89,(106) 45.5(0.98+5.5),(116) 4.45+0.63+5.55,(117)5.28(2.9+1.28),(107) 0.96-0.28+0.04-0.72,(108)12.7+12.5+0.5,(118)5.25+7.86-2.86+4.75,(120)9.42+7.39+1.58,(130) 4.26+5.48-1.26+4.52,(121)18.4-1.6-5.4,(131) 14.67+25.91+15.33+4.09,(122

8、)75.7+39.4-23.86,(132) 10.75-(2.40.86),(123)21.21+38.38-9.79,(133) 9.61-4.38+0.35,(124)47.28+1.39+52.72,(134) 3.87+4.92+1.13,(125)2.45-1.68+1.54,(135) 46.24-8.66-1.34,(126)15-8.131.87,(136) 21.99.220.78+8.1,(127)5.14+3.2256.302,(137) 35.47+39.8812.37,(128)3.95+5.36-1.95,(138) 93.21-5.9914.01,(150)1.

9、3+2.83+8.7+0.17,(140) 42.37(12.379.78),(151)2.472.2-3.8+7.53,(141) 38.78-19.59+41.22-30.41,(142) 1.9+19.9+199.9+0.3(152) 6.89+4.7+2.11+5.3,(143)429+31.1+2.04,(153) 7.462.37-1.63,(144)100-27.2-42.8,(154) 14-(3.65+0.24),(145)9-(3.02+1.25),(155) 70.8-1.25-1.75,(146)1.8-1.57+0.2,(156) 5.81+8.3+4.19+11.7

10、,(147) 5.03-2.5+0.96,(157)4.2+7.64+5.8+2.36,(148) 35.72(5.9+5.72),(158)14.282.637.37,(160)6.21-3.8+2.2,(170) 4.7+7.69+5.3+2.31,(161)6.03+3.7+2.97,(171) 53.7813.637.4+6.22,(162) 17.43-6.572.43,(172)60-(21.58.8)+7.3,(173)9.5+4.856.13,(163) 20.47(1.47+6.8),(164) 13.26+4.71+3.47+5.29,(174) 75.8-(15.3-4.

11、8),(165)22.74+8.6813.74,(175) 51.27-8.66-1.34,(166)12.56-6.643.36,(176) 28.43.961.04+4.6,(167)45.5(0.98+5.5),(177) 70.87.251.75(168)13.6+7.94+6.4,(178) 5.81+8.3+4.19+11.76756193207,(190)11.72-7.85-(1.26+0.46),0.9+1.08+0.92+0.1,(191)15.37+28.44+12.56,13.596.910.09,(192)12.64-(3.96+4.64),(179)(180)(18

12、1)(182)(183)(184)(185)(186)(187)(188)4.58+3.38+(5.48+6.62)(193)36.26-4.78+3.74,73.75-(4.3+8.75)(194)7.34+7.57+12.66+6.43,5-(4.19-2.83),(195)78.6523.1214.88,1.39+0.72+0.61+3.28,(195)4.58+2.39+(5.42+7.61),8-3.7-6.3,(196)8.27+5.84+1.73+2.16,8.28-(1.28+3.7),(197)18.51-9.08-0.92,.(199)7.85+6.76+2.15(209)

13、 3.781.46+1.54,(200)18.43-3.76-7.24(210) 8.45-(5.45+2.98);,(201)21.65+(4.8-3.65)(211) 3.01+8.2+6.99+1.8,(202)9.64(4.64-1.23)(212) 4.3(5.98-5.7),(203)2.7+17.6+3.3-5.6(213) 5.520.550.45,(204)9.87-3.5+2.138.5(214) 19.6-26.72+80.4-3.28,(205)5.64+4.97+0.03,(215) 27.510.80.2,(216)43.5+18-13.5,(206)10.933.

14、744.26,(207)10-6.8-3.2,(217) 63.5-(43.5+20),(224)10-4.445.56,(218) 75.3624.9+24.6425.1,(219) 12.566.643.36,(225) 32.63+7.896.4,(220)45.5(0.98+5.5),(226) 3.97+0.7-1.32,(221)6+7.94+6.4,(227) 30-(3.8+0.75),(222) 5.41+3.46-2.46,(228)75.6-(14.3-8.3),(223) 2.03-0.18-2.82+7.97,參考答案：(1) 7.4+12.86=20.26;7.4+

15、128620.26(2) 20-5.674=14.326;20-£67414326(3) 141.2-48.98=92.22;141.2-4S.9892.22(4) 102+4.36=106.36;102+4.3610636(5) 32.15-27.45=4.7;32.15-27.454.7驗算：27.45十4.732.15(6)12.9+5.01=17.91;12.95.0117.91驗算：1791-5.01-29.46-(9.46+3.8),=29.46-9.46-3.8,=20-3.8,=16.2;(8) 15.75+0.65-2.75+3.35,=(15.75-2.75)+(

16、0.65+3.35),=13+4,二17；(9) 65.71-4.99,=65.71-(5-0.01),=65.71-5+0.01,=60.71+0.01,=60.72;(10) 12.42+0.48=12.9,(11) 0.56+11.534=12.094,(12) 44-22.13=21.87,44-22-1321787(13) 91-22.035=68.965,91-22.0356&665(14) 52.6+21.237=73.837,52.6+21.23773.E37(15) 9.15-2.18=6.97.9.15-2.186. 97(16) 3.85-1.5+1.32,=2.

17、35+1.32,=3.67;(17) 15.4+6.87=22.271 5.4+6.872 2.27驗算：22.27-15.46.87(18) 3.56+27.84=31.43. 56+27.8431.40驗算：31.4-27484355(19) 100-82.13=17.87I00-82,1317.37驗算：1 7.E74-82.13100.00(20)123.56-47.9+51.7=127.36123.56-47,975.65+51.7127.35驗算：127.36-51.7T5.66+47.9123.56(21) 2.7+3.1+2.9+3.2,=2.7+(3.1+2.9)+3.2,=

18、2.7+6+3.2,=11.9.(22) 28.42+19.48=47.928.42十19.4B47.90驗算：4-9-29,4219.40(23)42.56+3.124=45.68442.56+3,12445*6B4驗算：45.9B43,124-30.75=50.25550.25驗算：5Q.25+30.7581.00(25)15.6十0.237=15.83715.6十0.23715.837驗算：15,837-15.60.237(26) 148.2-25.62-24.38=148.2-(25.62+24.38),=148.2-50,=98.2.(27) 4.52-0.74-0.26=4.52-

19、(0.74+0.26)=4.52-1=3.52;(28) 0.42+5.4+1.58+2.6=(0.42+1.58)+(5.4+2.6)=2+8=10;(29) 5.9+28.65-16.57=17.98;2 8.65+5.93 4.5一5-16.571 7.98(30) 57.5-3.25-16.75,=57.5-(3.25+16.75),=57.5-20,=37.5;(31) 6.02+3.6+1.98=6.02+1.98+3.6,=8+3.6,=11.6;(32) 1.29+3.7+2.71+6.3=(1.29+2.71)+(3.7+6.3),=4+10,=14;(33) 3.07-0.

20、38-1.62=3.07-(0.38+1.62),=3.07-2,=1.07;(34) 3.25+1.79-0.59+1.75=(3.25+1.75)+(1.79-0.59),=5+1.2,=6.2;(35) 7.5+4.9-6.1=12.4-6.1,=6.3;(36) 14.8+7.9-4.8=14.8-4.8+7.9,=10+7.9=17.9(37) 2.608+2.84=5.448,2.608+2.345.448(38) 6.07-3.869=2.201,6.07-3,8692. 201(39) 1.5-0.306=1.194,L5-0.3061.194(40) 76.8+26.82=1

21、03.62,76.8+26.82103/62(41) 102.07-37.257=64.813,102.07-37.25764.813(42)48.64+18.6=67.24.48. 64+18.667. 24(43) 54.75-5.25-14.75,=54.75-(14.75+5.25),=54.75-20,=34.75;(44) 4.68+14.79+5.32-10.79,=(4.68+5.32)+(14.79-10.79),=10+4,=14;(45) 48.9-12.7-0.3,=48.9-(12.7+0.3),=48.9-13,=35.9;(46) 56.4-39.7+24.3,=

22、16.7+24.3,=41;(47) 3.6-2.8+3.4-7.2,=(3.6+13.4)-(2.8+7.2),=17-10,=7；(48) 3.67+18.5+6.33,=(3.67+6.33)+18.5,=10+18.5,=28.5;(49) 120-17.83-2.17,=120-17.83-2.17,=120-(17.83+2.17),=120-20,=100;(50) 17.17-6.8-3.26.17=(17.17-6.17)-(6.8+3.2),=11-10,=1；(51) 73.8-1.64-13.8-5.36=73.8-13.8-(1.64+5.36),=60-7,=53;

23、(52) 6.75-(0.9+3.75)=6.75-3.75-0.9,=3-0.9,=2.1;(53) 27.38-5.34+2.62-4.66=22.04+2.62-4.66,=24.66-4.66,=20;(54) 35.72-4.9-(5.72+5.1)=35.72-(4.9+5.72+5.1),=35.72-15.72,=20;(55) 0.73-0.25-0.73+0.25=0.75-0.75-0.25+0.25,=0-0.25+0.25,=0-0,=0；(56) 5.3+0.1+5.3-0.1=5.3+5.3+0.1-0.1,=10.6+0.1-0.1,=10.7-0.1,=10.

24、6;(57) 12.7-4.8-5.2.=12.7-(4.8+5.2);=12.7-10,=2.7.(58) 23.25-6.75-3.25=23.25-(6.75+3.25),=23.25-10,=13.25.(59) 4.58+2.39+(5.42+7.61)=(4.58+5.42)+(2.39+7.61)=10+10,=20;(60) 9.05-3.86-3.14,=9.05-(3.86+3.14),=9.05-7,=2.05;(61) 20-9.18-0.82,=20-(9.18+0.82),=20-10,=10.=15.45;(74) 9.4+0.3-6.4,=(9.4-6.4)+0

25、.3,=3+0.3,=3.3;(75) 15.25+4.72+4.75+5.28,=(15.25+4.75)+(4.72+5.28),=20+10,=30;(76) 34.823-(4.82+15.2),=34.823-4.82-15.2,=30.003-15.2,=14.803;(77) 12.7-4.8-5.2,=12.7-(4.8+5.2),=12.7-10,=2.7;(78) 3.1+25.78+6.9,=(3.1+6.9)+25.78,=10+25.78,=35.78;(79) 73.8-1.64-13.8-5.36,=(73.8-13.8)-(1.64+5.36),=60-7,=5

26、3(80) 2.15+8.73+1.27+7.85=(2.15+7.85)+(8.73+1.27),=10+10,=20;(81) 11.87-(8.2+1.87),=11.87-1.87-8.2,=10-8.2,=1.8;(82) 5.42-3.87-1.13,=5.42-5,=0.42;(83) 4.38-1.56+0.62-0.44,=(4.38+0.62)-(1.56+0.44),=5-2,=3；(84) 46.7-15.03-4.97=46.7-(15.03+4.97),=46.7-20,=26.7;(85) 4.52+0.61+1.39+6.48=(4.52+6.48)+(0.61

27、+1.39),=11+2,=13;(86) 4.27(1.961.73)(62) 6.53-(1.53+2.6),=6.53-1.53-2.6,=4-2.6,=1.4.(63) 5.52-1.074-0.926,=5.52-(1.074+0.926),=5.52-2,=3.52.(64) 4.21+1.04+0.79,=4.21+0.79+1.04,=5+1.04,=6.04(65) 1.36+4.85+2.64+6.15,=(1.36+2.64)+(4.85+6.15),=4+11,=15;(66) 83.7-12.83-0.17,=83.7-(12.83+0.17),=83.7-13,=7

28、0.7;(67) 4.32+5.43+6.68,=4.32+6.68+5.43,=11+5.43,=16.43;(68) 17.17-6.8-3.2,=17.17-(6.8+3.2),=17.17-10,=7.17;(69) 1+12.7+5.9+17.3=1+(12.7+17.3)+5.9,=1+30+5.9,=36.9;(70) 270-42.5-17.5=270-(42.5+17.5),=270-60,=210;(71) 15.68-(7.78-4.32)-2.32,=15.68-7.78+4.32-2.32,=(15.68+4.32)-(7.78+2.32),=20-10,=10;(7

29、2) 0.9+9.9+99.9+999.9,=1-0.1+10-0.1+100-0.1+1000-0.1,=(1+10+100+100。(0.1+0.1+0.1+0.1),=1111-0.4,=1110.6(73) 25.46-8.23-1.76,=25.46-(8.23+1.76),=25.469.99=4.27-0.23,=4.04;(87) 7.27-(1.98+0.27),=7.27-0.27-1.98,=7-1.98,=5.02;(88) 13.7+8.65-9.628,=22.35-9.628,=12.722;(89) 12.8-(4.38+1.614)=12.8-5.994=6.

30、806(90) 15.17-(3.6+4.9),=15.17-8.5,=6.67;(91) 35.6+(12.6-4.4),=35.6+8.2,=43.8;(92) 16.4+3.5+83.6+166.5=(16.4+83.6)+(3.5+166.5)=100+170=270;(93) 4.65-2.55-1.45,=4.65-(2.55+1.45),=4.65-4,=0.65;(94) 1.28+0.86+38.72,=(1.28+38.72)+0.86,=40+0.86,=40.86;(95) 25.74-3.57-6.43,=25.74-(3.57+6.43),=25.74-10,=15

31、.74;(96) 14.5-4.68-5.32,=14.5-(4.68+5.32),=14.5-10,=4.5;(97) 0.485+0.64+3.36,=0.485+(0.64+3.36),=0.485+4,=4.485;(98) 72.51-9.34-12.66,=72.51-(9.34+12.66),=72.51-22,=50.51;(99) 14.02-4.5+0.98,=(14.02+0.98)-4.5,=154.5,=10.5;(100) 5.76+2.43+0.24+10.57,=(5.76+0.24)+(2.43+10.57),=6+13,=19;(101) 9.28-(3.2

32、8+2.55),=9.28-3.28-2.55,=6-2.55,=3.45;(102) 9.5+4.85-6.13,=14.35-6.13,=8.22;(103) 10.75-1.86-2.75-3.16,=(10.75-2.75)-(1.86+3.16),=8-5.02,=2.98(104) 1.3+0.94+0.06+7.7,=(1.3+7.7)+(0.94+0.06),=9+1,=10;(105) 4.45+0.63+5.55,=(4.45+5.55)+0.63,=10+0.63,=10.63;(106) 45.5-(0.98+5.5),=45.5-0.98-5.5,=(45.5-5.5

33、)-0.98,=40-0.98,=40-(1-0.02),=40-1+0.2,=39.02;(107) 0.960.28+0.040.72,=(0.96+0.04)-(0.28+0.72),=11,=0.(108) 12.7+12.5+0.5,=12.7+(12.5+0.5),=12.7+13,=25.7(109) 0.6+0.94-0.208,=1.54-0.208,=1.332;(110) 27.73-(4.73-1.85),=27.73-4.73+1.85,=23+1.85,=24.85;(111) 3.84+26.5-(20-8.6),=3.84+26.5-11.4,=3.84+15.

34、1,=18.94(112) 7.38-5.14+3.62-2.86,=(7.38+3.62)-(5.14+2.86),=11-8,二3;(113) 5.86+13.08-9.27,=18.94-9.27,=9.67;(114) 25.4-(15.4-6.4),=25.4-15.4+6.4,=10+6.4,=16.4;(115) 47.23-7.235.89,=40-5.89,=34.11.(116) 4.45+0.63+5.55,=4.45+5.55+0.63,=10+0.63,=10.63;(117) 5.28(2.9+1.28),=5.28-1.28-2.9,=4-2.9,=1.1;(11

35、8) 5.25+7.86-2.86+4.75,=(5.25+4.75)+(7.86-2.86),=10+5,=15;(119) 0.96-0.28+0.04-0.72,=(0.96+0.04)-(0.28+0.72),=1-1,=0.(120) 9.42+7.39+1.58,=(9.42+1.58)+7.39,=11+7.39,=18.39;(121) 18.4-1.6-5.4,=18.4-(1.6+5.4),=18.4-7,=11.4(122) 75.7+39.4-23.86,=115.1-23.86,=91.24;(123) 21.21+38.38-9.79,=59.59-9.79,=49

36、.8;(124) 47.28+1.39+52.72,=47.28+52.72+1.39,=100+1.39,=101.39;(125) 2.45-1.68+1.54,=0.77+1.54,=2.31(126) 15-8.13-1.87,=15-(8.13+1.87),=15-10,二5；(127) 5.14+3.225-6.302,=8.365-6.302,=2.063;(128) 3.95+5.36-1.95,=3.95-1.95+5.36,=2+5.36,=7.36;(129) 13.67-(5.45+3.67),=13.67-5.45-3.67,=13.67-3.67-5.45,=10-

37、5.45,=4.55;(130) 4.26+5.48-1.26+4.52,=(4.52+5.48)+(4.26-1.26),=10+3;=13;(131) 14.67+25.91+15.33+4.09,=(14.67+15.33)+(25.91+4.09),=30+30,=60(132) 10.75-(2.4-0.86),=10.75-1.54,=9.21;(133) 9.61-4.38+0.35,=5.23+0.35,=5.58;(134) 3.87+4.92+1.13,=(3.87+1.13)+4.92,=5+4.92,=9.92;(135) 46.24-8.66-1.34,=46.24-

38、(8.66+1.34),=46.24-10,=36.24;(136) 21.9-9.22-0.78+8.1,=21.9-(9.22+0.78)+8.1,=21.9-10+8.1,=11.9+8.1,=20;(137) 35.47+39.88-12.37,=(35.47-12.37)+39.88,=23.1+39.88,(150) 1.3+2.83+8.7+0.17,=(1.3+8.7)+(2.83+0.17),=10+3,=13;(151) 2.47-2.2-3.8+7.53,=(2.47+7.53)-(2.2+2.8),=10-5,=5(152) 6.89+4.7+2.11+5.3,=(6.

39、89+2.11)+(4.7+5.3),=9+10,=19;(153) 7.462.37-1.63,=7.46-(2.37+1.63),=7.46-4,=3.46;(154) 14-(3.65+0.24),=14-3.89,=10.11;(155) 70.8-1.25-1.75,=70.8-(1.25+1.75),=70.8-3,=67.8;(156) 5.81+8.3+4.19+11.7,=(5.81+4.19)+(8.3+11.7),=10+20,=30;(157) 4.2+7.64+5.8+2.36,=(4.2+5.8)+(7.64+2.36),=10+10,=20;(158) 14.28

40、-2.63-7.37,=14.28-(2.63+7.37),=14.28-10,=4.28;(159) 6.8+5.26+3.74+3.2,=(6.8+3.2)+(5.26+3.74),=10+9,=19;(160) 6.21-3.8+2.2,=2.41+2.2,=4.61;(161) 6.03+3.7+2.97,=(6.03+2.97)+3.7,=9+3.7,=12.7;(162) 17.43-6.57-2.43,=17.43-(6.57+2.43),=62.98;(138) 93.21-5.99-14.01,=93.21-(5.99+14.01),=93.21-20,=73.21;(139

41、) 15.37+28.94+4.63+1.06,=(15.37+4.63)+(28.94+1.06),=20+30,=50;(140) 42.37-(12.37-9.78),=42.37-12.37+9.78,=30+9.78,=39.78(141) 38.78-19.59+41.22-30.41,=38.78+41.22-19.59-30.41,=(38.78+41.22)-(19.59+30.41),=80-50,=30;(142) 1.9+19.9+199.9+0.3=1.9+19.9+199.9+0.1+0.1+0.1,=(1.9+0.1)+(19.9+0.1)+(199.9+0.1)

42、,=2+20+200,=222;(143) 429+31.1+2.04,=429+(31.1+2.04),=429+33.14,=462.14,(144) 100-27.2-42.8,=100-(27.2+42.8),=100-70,=30,(145) 9-(3.02+1.25),=9-4.27,=4.73,(146) 1.8-1.57+0.2,=1.8+0.2-1.57,=2-1.57,=0.43(147) 5.03-2.5+0.96,=2.53+0.96,=3.49;(148) 35.72-(5.9+5.72),=35.72-5.9-5.72,=35.72-5.72-5.9,=30-5.9

43、,=24.1;(149) 25-4.7+5.3,=20.3+5.3,=25.6;=17.43-9,=8.43;(163) 20.47-(1.47+6.8),=20.47-1.47-6.8,=19-6.8,=12.2;(164) 13.26+4.71+3.47+5.29,=(13.26+3.47)+(4.71+5.29),=16.73+10,=26.73;(165) 22.74+8.68-13.74,=(22.74-13.74)+8.68,=9+8.68,=17.68(166) 12.56-6.64-3.36,=12.56-(6.64+3.36),=12.56-10,=2.56;(167) 45

44、.5(0.98+5.5),=45.5-0.98-5.5,=45.5-5.5-0.98,=40-0.98,=39.02;(168) 13.6+7.94+6.4,=(13.6+6.4)+7.94,=20+7.94,=27.94;(169) 15.19+3.36+4.64+4.81,=(15.19+4.81)+(3.36+4.64),=20+8,=28(170) 4.7+7.69+5.3+2.31,=(4.7+5.3)+(7.69+2.31),=10+10,=20.(171) 53.78-13.6-37.4+6.22,=(53.78+6.22)-(13.6+37.4),=60-51,=9.(172)

45、 60-(21.5-8.8)+7.3,=60-12.7+7.3,=47.3+7.3,=54.6(173) 9.5+4.85-6.13,=14.35-6.13,=8.22;(174) 75.8-(15.3-4.8),=75.8-10.5,=65.3;(175) 51.27-8.66-1.34,=51.27-(8.66+1.34),=51.27-10,=41.27;(176) 28.4-3.96-1.04+4.6,=(28.4+4.6)-(3.96+1.04),=33-5,=28;(177) 70.87.251.75=70.8-(7.25+1.75),=70.8-9,=61.8;(178) 5.8

46、1+8.3+4.19+11.7=(5.81+4.19)+(8.3+1.7),=10+10,=20;(179) 794-198,=794-(200-2),=794-200+2,=594+2,=596;(180) 6756-193-207,=6756-(193+207),=6756-400,=6356;(181) 0.9+1.08+0.92+0.1,=(0.9+0.1)+(1.08+0.92),=1+2,=3；(182) 13.59-6.91-0.09,=13.59-(6.91+0.09),=13.59-7,=6.59(183) 4.58+3.38+(5.48+6.62)=4.58+5.48+(3

47、.38+6.62),=10.06+10,=20.06;(184) 73.75-(4.3+8.75)=73.75-8.75-4.3,=65-4.3,=60.7;(185) 5-(4.19-2.83),=5-1.36,=3.64;(186) 1.39+0.72+0.61+3.28,=(1.39+0.61)+(0.72+3.28),=2+4,=6；(187) 8-3.7-6.3,(198) 0.09+0.6+5.91+3.4,=(0.09+5.91)+(0.6+3.4),=6+4,=10.(199) 7.85+6.76+2.15=7.85+2.15+6.76,=10+6.76,=16.76;(200

48、) 18.43-3.76-7.24=18.43-(3.76+7.24),=18.43-11,=7.43;(201) 21.65+(4.8-3.65)=21.65-3.65+4.8,=18+4.8,=22.8;(202) 9.64-(4.64-1.23)=9.64-4.64+1.23,=5+1.23,=6.23;(203) 2.7+17.6+3.3-5.6=2.7+3.3+(17.6-5.6),=6+12,=18;(204) 9.87-3.5+2.13-8.5=9.87+2.13-(3.5+8.5),=12-12,=0.(205) 5.64+4.97+0.03,=5.64+(4.97+0.03),=5.64+5,=10.64;(206) 10.93-3.74-4.26,=10.93-(3.74+4.26),=10.93-8,=2.93;(207) 10-6.83.2,=10-(6.8+3.2)=10-10,=0；(208) 5.81+8.3+4.19+11.7,=(5.81+4.19)+(8.3+11.7),=10+20,=30;(209) 3.78-1.46+1.54,=2.14+1.54,=3.68.(210) 8.45-(5.45+2.98);,=8.455.452.98,=8-(3.7+6.3),=8-10,=-2；(188) 8.28-(1.2