(完整)小數(shù)除法脫式運(yùn)算+簡(jiǎn)算260道含答案(2),推薦文檔

1、小數(shù)除法脫式運(yùn)算+簡(jiǎn)算260 道一計(jì)算題（共50 小題）1用你喜歡的方法計(jì)算32X 12.5X 0.256.1 X4.2+5.8X6.11.7+ 2.5+0.4 16.1 4.2 5.8.3脫式計(jì)算4.8+ (1.2+0.5)12.812.8 + 571.4+ (7X6)4用你喜歡的方法計(jì)算0.65X101-0.6512.6-3.25+6.756.35 + 0.2+0.55.7X 1.2+191.25X 3.63X0.8.5我能用喜歡的方法計(jì)算下面各題0.11 X 1.8+8.2X0.113.5 3.5X 0.980.75X 18 + 0.150.25X4.78X8.6能簡(jiǎn)算的要簡(jiǎn)算17.3+

2、0.125+ 814.72X0.7+5.28X0.7第 2 頁(yè)（共19頁(yè)）3.5+ 0.568.5X9.9+0.82.7.遞等式計(jì)算，有簡(jiǎn)便運(yùn)算的用簡(jiǎn)便方法38.75- (24.5+8.75)0.4X2.32X0.250.75X1014.2 3.2X0.97.56X99+7.5670.3- 17.48+7.63.64 + 5.2X23.321.8-0.8-1.2X545+ (5.25+0.25)16.5X101-16.50.96 + 0.3X141.25X4X2.5X836.45+ (0.82+3.4X0.2)9.07-2.64 + 0.41.5X10112.6 7.5+8.313.6X0.8

3、5-3.6X0.85104 8.586.4 + 6.4 0.40.25 6.2 0.423X6.5+17X6.536+0.4X0.25(24.618.1) X3.47.6 9.9+7.6 0.113.6X0.8X12.523.9X8.5-3.9X8.5(2.55+9.6+ 16) +0.429.2+0.25+4第4頁(yè)（共19頁(yè)）8脫式計(jì)算（能簡(jiǎn)算的要簡(jiǎn)算）第 6頁(yè)（共19頁(yè)）0.75X4X0.25X49.6+9.9X 9915.58+ 8.2 0.724.536+ 0.8+ 142.8X3.6+1.4X 2.86.3X 10.1.9脫式計(jì)算（能簡(jiǎn)算的要用簡(jiǎn)算）4.2X7.8+2.2X4.29.

4、5X101(8X3.82) X1.250.125X 720.6X3.9X0.842X0.39+4.2X 6.110脫式計(jì)算，能簡(jiǎn)算的要簡(jiǎn)算0.25X1.25X 1618.9 18.9+1.4 8.37X 1.2-8.37X0.243X11.8+5.7X118.11用簡(jiǎn)便方法計(jì)算6.2+5.18+2.815.35- (5.35+7.2)3.63- 1.25+17.37-8.7551.72-8.66- 1.34.12脫式計(jì)算，能簡(jiǎn)算的要簡(jiǎn)算12.9- 1.68-2.32567+20 + 5.0.7X 101 0.70.125X 4.95X813用遞等式計(jì)算，能簡(jiǎn)算的要簡(jiǎn)算第 8頁(yè)（共19頁(yè)）20.

5、16+ 7.2+9.86.2X2.7+6.5X7.332.8+9.6+7.214脫式計(jì)算：能簡(jiǎn)算的要簡(jiǎn)算15.89 (5.89+6.98)0.25X 13.7X0.432.7X28+7.3X 2815X9.4-424.9+12.87-5.380.05X0.7X 20X1.7.15計(jì)算下面各題，能簡(jiǎn)算的要簡(jiǎn)算能簡(jiǎn)算的要簡(jiǎn)算.5.04X28(15.47.8) X 3.53.2X4.6+3.2X5.40.25X17.4X 420- 6.72-3.288.33+7.45+1.67+2.5516脫式計(jì)算0.2X0.6X0.5X4(7.5- 2.3X0.4) +0.011.2X0.25+2.8X0.251

6、78.8+ (26.4-5.6)3.6 1.28+3.093.82+2.9+0.18+9.19.43 (6.28- 1.57)17能簡(jiǎn)算的要簡(jiǎn)算21.32 (6.32+8.3)13.75 (3.75+6.48)15 7.35 2.6518混合運(yùn)算，能簡(jiǎn)便就簡(jiǎn)便19.81 2.68-8.32 5.6+6.6 5.6+6.6 0.81 義 27+0.19X 27 101 X0.19-0.19.19用簡(jiǎn)便方法計(jì)算9.08- 1.76- 4.2418.38 (5.38+1.8) - 8.217.45 (8.76- 6.55)12.87+3.98- 3.87.20脫式計(jì)算，能簡(jiǎn)便的用簡(jiǎn)便方法計(jì)算10.8

7、+ (3.94+S.86) X 0.80.65X 20112.5X3.9X0.839.8 X 0.25X 437.6X 8+37.6X 20.78 X 99+0.78.第 5頁(yè)(共19頁(yè))0.49X9.90.05X0.7X20X1.721.8-7.22-2.7812.75+ 14.6- (1.3+8.2)45.2X66.7+66.7X 53.8+66.7 0.25X0.8X0.125X0.40.125X 36X (4+0.5) -36 (6.1 4.6) X 0.8 1 X 0.36 15.6 (4.1+0.2+6.86-0.7)5- (1 - 1.2X0.8) +41 + 0.25+0.4X

8、0.613.6X3-40.6+ 225.8+10.5- (5 - 3.5)1.42 - 0.36 + 6X0.649.5 義 0.2 - 2.07+ 236.7+3.3+4.4+5.622.計(jì)算下面各題(能簡(jiǎn)算的要簡(jiǎn)算)50X (0.8+0.4)7.34X 2.1+7.34X 6.8+7.34X 1.120.5+ 1.25+ 0.89.88X 9+9.88.23.計(jì)算下列各題(能用簡(jiǎn)便算法的要用簡(jiǎn)便算法).12.6+ (1.02+3.18)5.7X6.9+4.3X6.9(0.81+2.7) +0.9 (8.47.9) +0.25 X1.2.25.能簡(jiǎn)算的用簡(jiǎn)便方法計(jì)算.(寫(xiě)出主要簡(jiǎn)便過(guò)程，無(wú)過(guò)

9、程不得分)1.6X 3.9X 1.254.87X 2.34+48.7 X 0.2662.5X 3.2X 12.53.95X 7.6+3.95X 3.4 - 3.95.26 .計(jì)算下面各題，能簡(jiǎn)算的要簡(jiǎn)算7.8X 6.9+2.2X 6.92.36X2.5X 4102X 0.454.19X99+4.1921.36+ 0.8 12.93.2+ 0.8X 0.2627 .計(jì)算(能簡(jiǎn)算的要簡(jiǎn)算).6.33X 101 6.331.6X55.4-55.4X 0.6 17.68-5.2+2.7X1.5(1.1-0.78)義(2.7- 1.95)35.6-5X 1.7315+0.2 + 2.528 .脫式計(jì)算(

10、能簡(jiǎn)算的要簡(jiǎn)算)2.5X 1.37X0.44.8X0.25X250.89X4.8+0.89X5.2101X0.78X208.8X 1.25X154.3X0.8X529 .計(jì)算下面各題，能簡(jiǎn)算的要簡(jiǎn)算.44.28+ 0.9+ 4.10.25X 0.39X47.6+7.6X 99第11頁(yè)（共19頁(yè)）9.0722.78+3.44.8X99+4.136.3X10.130.下面各題，能簡(jiǎn)算的就要簡(jiǎn)算.5.8+3.8X0.251.7X (4.65-3.87)1.25X4.3X0.84.5X1020.54X 101 -0.543.4X2.5+6.6X2531.計(jì)算下列各題.0.45X12X0.22.8-2.

11、8X0.1510-6.06+8.532.用簡(jiǎn)便方法計(jì)算.0.25X9.87X 46.2X2.1 -2.10.9 0.8 1000.73X1022.8X1.43+0.5772 0.81+10.36X0.25X 1.87.06X2.4-5.836.2X 1.8+13.8X 1.80.125X2.3X8(6.8+2.6) X 50.23X98.33.能用簡(jiǎn)便方法的用簡(jiǎn)便方法計(jì)算12.5X32X2.56.8 9.9第8頁(yè)(共19頁(yè))7.2+1.8X (3.4-2.9).8.5+6.85- 6.353.9+0.1 3.9+0.112.6 - (3.75+5.08)34 .用你喜歡的方法計(jì)算.3.4X 9

12、+3.46.4+0.8 1.5X43.78+0.25+ 417+ (1.2+0.5) X 5.35 .用你喜歡的方法計(jì)算2.5X 1.25X8X0.412.8X1.7+87.2X1.7100-4.35- 5.65.第10頁(yè)(共19頁(yè))36 .用遞等式計(jì)算（能簡(jiǎn)算的要簡(jiǎn)算）4+7.6X 1526.08+ 0.25+419.7+ (80.5+ 35X0.2)37 .計(jì)算，能簡(jiǎn)算的要簡(jiǎn)算.1.25X2.25X 0.89.7X99+9.74.8X7.8+78X0.523.65X 10.1.38 .計(jì)算下面各題.(能簡(jiǎn)算的用簡(jiǎn)便算法) 12.366.49 3.518.5X 3.8+8.5X 6.2 17

13、.3X0.25X8 15.32 1.8X5 3.46 199X2.63.6+ (1.3+0.6) X 540 .計(jì)算，能簡(jiǎn)算的要簡(jiǎn)算6.09 9.13+ 8.33.84X 9.6+0.96X 61.64.86X 995.68 X 4+4.32 + 0.256.4X 4.5+3.6X 4.5.41 .脫式計(jì)算.10.5+61 X18 (3.14+12.6) +8 4.5+ (15 + 3)75+448+4X19.42 .計(jì)算：(18.5X 3.8+3.8X2.5) +0.1932 ( 7.25+0.75X 8) +50.43 .脫式計(jì)算，能簡(jiǎn)算的就簡(jiǎn)算：44 .32- (3.4 1.2)12-

14、0.62-4.38.44.用簡(jiǎn)便方法計(jì)算下面各題.5.12+2.54+4.8812.5X 17.8X0.80.24X0.48X49.9X 2.59.4X 5.8+10.6X5.80.66X 1014.8X0.252.33X0.5X 41.3X 2.5+0.7X 2.51.26X 0.6+1.26X 0.4102X 0.550.034X 0.5X 0.245.計(jì)算.(怎樣簡(jiǎn)便就怎么計(jì)算)13.38+0.98=7.02- 2.986.57 (0.68 0.39+0.32)13.8+ (1.38X0.2)30.7-0.12X2-0.767.8X 1.0118.4-6.5+1.6+3.57.8 + 0

15、.6+7.8+ 0.412.13+7.5 1.13+2.859.6X3.6+7.2X0.2.0.125X 8.89.4X 3.2+6X0.3246 .計(jì)算下面各題，能簡(jiǎn)算得要簡(jiǎn)算.96+ (100X 0.48)3.6+ (1.2+0.5) X 6(967- 31) + ( 17+48)72X 10.1+27X 10.1.47 .用自己喜歡的方法計(jì)算.54 + (6.86+3.94)3.4X 7.8 + 3.948 .用簡(jiǎn)便方法計(jì)算0.486+0.01+3.9917.5X 2.3 7.5X2.31.25X11 X4X0.84.8X39+61X4.845.55 (6.82+15.55)3.2 99

16、+3.22.5X56+4.5X56(31.6 11.7) +2.5 + 43.6 0.9+3.6 0.149.計(jì)算下列各題.（能簡(jiǎn)算的要簡(jiǎn)算）7.5 2.4 + 0.8X2.512.5X 17+83X 12.5 399X2.525+ (2.5+ 0.4)3.25X67+5.75X 67+67 230+ 2.5X 7.56.3+0.84+3.7+8.16 100 (2.72+10.8) +0.250 .脫式計(jì)算0.8X4.5+1.2X450.25X3.25X 46.72+3.2 + 2.521.36+0.4 23.4第23頁(yè)（共19頁(yè)）小數(shù)除法脫式運(yùn)算+簡(jiǎn)算260道參考答案與試題解析一.計(jì)算題(

17、共 50 小題)1.【解答】解：(1) 32X12.5X0.25=4X 8X12.5X 0.25= (4X0.25)義(8X 12.5) =1X100=100(2) 6.1X 4.2+5.8X6.1=6.1X (4.2+5.8) =6.1X10=61(3) 1.7+ 2.5+0.4=1.7+ (2.5X0.4) =1.7+ 1=1.7 (4) 16.1-4.2- 5.8=16.1- (4.2+5.8) =16.1-10=6.1 2.【解答】(1) (0.6X0.8+0.12) + 1.2=0.6 + 1.2=0.5 答：商是 0.5. (2) (14.81+5.19) 乂 ( 14.81 5.

18、19) =20X 9.62=192.4 答：積是 192.4. (3) (2.7+4.5) + 12 X 0.3= 7.2+12 X 0.3=0.6X 0.3=0.18答： 積是 0.18.3.【解答】解：4.8+ (1.2 + 0.5) =4.8+ 2.4=2 12.8 12.8 + 5=12.8 2.56=10.2471.4+ (7X6) =71.4+ 7 + 6=10.2+ 6=1.7 4.【解答】 解：0.65 X 101 - 0.65=0.65X ( 101 - 1) =0.65X 100=65 12.6-3.25+6.75=12.6+ (6.75-3.25) =12.6+3.5=1

19、6.16.35+0.2+0.5=6.35+ (0.2X0.5) =6.35+ 0.1=63.53)5.7X 1.2+ 19=5.7+ 19X 1.2=0.3X 1.2=0.36 1.25X3.63X0.8= ( 1.25X0.8) X 3.63=1 X 3.63=3.63 5.【解答】 解：0.11 X 1.8+8.2 X0.11=0.11X (1.8+8.2) =0.11 X 10=1.1 3.5 3.5X0.98=3.5X ( 1 0.98) =3.5 X 0.02=0.070.75X 18+0.15=0.75+ 0.15X 18=5X 18=900.25X4.78X 8=0.25X 8X

20、4.78=2X4.78=9.56 6.【解答】解： 17.3+ 0.125+ 8=17.3+ (0.125X8)=17.3+ 1=17.3 14.72X 0.7+5.28X 0.7= (14.72+5.28)義 0.7=20X 0.7=14 3.5 + 0.56= ( 3.5 + 0.7) + ( 0.56 + 0.7) =5 + 8=0.625 8.5 義 9.9+0.82=8.5 義(10 - 0.1 ) +0.82=8.5 X 10 - 8.5 義 0.1+0.82=85 - 0.85+0.82=85- (0.85- 0.82) =85- 0.03=84.97 7.【解答】 解：(1)

21、38.75-(24.5+8.75) =38.75- 24.5 - 8.75=38.75- 8.75 - 24.5=30 - 24.5=5.5; (2) 0.4 X 2.32 X0.25=0.4X 0.25X 2.32=0.1 X 2.32=0.232; (3) 0.75X 101=0.75X (100+1) =0.75 X 100+0.75 X 1=75+0.75=75.75; (4) 4.2 - 3.2 X 0.9=4.2- 2.88=1.32; (5) 7.56X 99+7.56=7.56X (99+1) =7.56X 100=756; (6) 70.3T7.48+7.6=70.3-2.3

22、=68;(7) 3.64 + 5.2X23.3=0.7X23.3=16.31; (8) 21.8-0.8- 1.2X5=27.25- 6=21.25;(9) 45+ (5.25 + 0.25) =45+ 21告；(10) 16.5X101 - 16.5=16.5X (101-1)=16.5X 100=1650; (11) 0.96+ 0.3X14=3.2X14=44.8; (12) 1.25X 4X2.5X8= (1.25X 8)義(4X2.5) =10X 10=100； ( 13) 36.45+ ( 0.82+3.4X0.2) =36.45 一 (0.82+0.68) =36.45+ 1.5

23、=24.3; (14) 9.07 -2.64 +0.4=9.07- 6.6=2.47; (15) 1.5 X 101=1.5X ( 100+1 ) =1.5 X 100+1.5 X 1=150+1.5=151.5; (16) 12.6 X 7.5+8.3=94.5+8.3=102.8; (17) 13.6X 0.85-3.6X0.85= (13.6-3.6) X 0.85=10X 0.85=8.5; (18) 104X8.5= (100+4) X8.5=100X 8.5+4X8.5=850+34=884; (19) 86.4-6.4 - 0.4=13.5- 0.4=13.1; ( 20) 0.

24、25X 6.2 X 0.4=0.25X 0.4X 6.2=0.1 X 6.2=0.62; (21) 23X6.5+17X6.5= (23+17) X 6.5=40X 6.5=260; (22) 36+0.4 X 0.25=90X0.25=22.5; (23) (24.6- 18.1) X 3.4=6.5X 3.4=22.1; (24) 7.6X 9.9+7.6 X0.1=7.6X (9.9+0.1) =7.6X 10=76; (25) 13.6X 0.8X 12.5=13.6X (0.8X12.5) =13.6X 10=136; (26) 23.9X8.5-3.9X8.5=(23.9-3.9)

25、 X 8.5=20X 8.5=170; (27) (2.55+9.6+ 16) +0.42= (2.55+0.6) +0.42=3.15+ 0.42=7.5; (28) 9.2 + 0.25+4=9.2+ (0.25X4) =9.2+1=928.【解答】 解：(1) 0.75X4X0.25X 4= (0.75X4) X (0.25X 4) =3X1=3 (2) 9.6+9.9X 99=9.6+9.9X (100- 1) =9.6+9.9X 100 -9.9=9.6+990- 9.9=989.7 (3) 15.58-8.2-0.72=1.9-0.72=1.18 (4) 4.536+ 0.8 +

26、14=5.67+ 14=0.405 (5) 2.8X 3.6+1.4X 2.8=2.8X ( 3.6+1.4) =2.8X 5=14 (6) 6.3X 10.1=6.3X (10+0.1) =6.3X 10+6.3x 0.1=63+0.63=63.63 9.【解答】解：(1) 4.2X7.8+2.2X4.2 =4.2X (7.8+2.2 ) =4.2X 10=42 (2) 9.5X 101=9.5X ( 100+1) =9.5X 100+9.5=950+9.5=959.5 (3) (8X3.82) X1.25= (8X 1.25) X3.82=10X 3.82=38.2 (4) 0.125X

27、72=0.125X 8 X 9=1 X 9=9 ( 5) 0.6X 3.9X0.8 =2.34X 0.8=1.872(6) 42 義 0.39+4.2X 6.1=42X 0.39+42 義 0.61=42X (0.39+0.61) =42X 1=42 10【解答】 解：(1) 0.25X1.25X16=0.25X 1.25X (2X8) = (0.25X2) 乂 (1.25 X8) =0.5X10=5(2) 18.9- 18.9-1.4=18.9- 13.5=5.4 (3) 8.37X 1.2 - 8.37X 0.2=8.37X (1.2 0.2) =8.37X 1=8.37(4) 43X 1

28、1.8+5.7X 118=43X 11.8+57X 11.8= ( 43+57) X 11.8=100 X 11.8=118011 .【解 答】 解：(1) 6.2+5.18+2.8=6.2+2.8+5.18=9+5.18=14.18(2)15.35- (5.35+7.2) =15.35-5.35-7.2=10-7.2=2.8 (3) 3.63- 1.25+17.37-8.75= (3.63+17.37) (1.25+8.75) =21- 10=11 (4) 51.72-8.66- 1.34=51.72- (8.66+1.34) =51.72- 10=41.72 12.【解答】解：(1)0.7

29、X 101 -0.7=0.7X (101 1)=0.7X100=70(2) 0.125X4.7X8=0.125X8X 4.7=1 X4.7=4.7(3) 12.9- 1.68- 2.32=12.9- (1.68+2.32)=12.9- 4=8.9 (4) 567+ 20+ 5=567+ (20X5) =567+ 100=5.67 13.【解答】 解： 20.16 + 7.2+9.8=2.8+9.8=12.6 ; 6.2 X 2.7+6.5 X 7.3=16.74+47.45=64.19 ; 32.8+9.6+7.2=9.6+ ( 32.8+7.2 )=9.6+40=49.6.14.【解答】解：

30、(1) 15.89 (5.89+6.98) =15.89 5.89-6.98=10- 6.98=3.02; (2) 0.25X 13.7X 0.4=0.25X 0.4X13.7=0.1X13.7=1.37; (3) 32.7X 28+7.3X28 = (32.7+7.3) X 28=40X 28=1120; (4) 15X9.4-42=141-42=99; (5) 4.9+12.87- 5.38=17.77-5.38=12.39; (6) 0.05 X 0.7 X 20X 1.7=0.05X 20義 0.7義 1.7=1 X0.7X 1.7=0.7X1.7=1.19,15.【解答】 解：(1)

31、 5.04X28= (5+0.04)義28=5X 28+0.04X 28=1401.12=141.12; (2) (15.4-7.8) X 3.5=7.6 X 3.5=26.6; (3) 3.2X4.6+3.2X5.4=3.2X (4.6+5.4) =3.2X10=32; (4) 0.25X17.4X 4=0.25X4X17.4=1X17.4=17.4; (5) 20- 6.72- 3.28=20- ( 6.72+3.28) =20- 10=10; (6) 8.33+7.45+1.67+2.55=8.3等1.67+7.45+2.55= (8.33+1.67) + (7.45+2.55) =10

32、+10=20.16.【解答】 解：(1) 0.2X0.6X0.5X4 = (0.2X0.5) X (0.6X4)=0.1 X 2.4=0.24;(2) (7.5 - 2.3X 0.4) + 0.01=(7.5 - 0.92) + 0.01=6.58+ 0.01=658; (3) 1.2 X 0.25+2.8 X 0.25= ( 1.2+2.8) X 0.25=4 X 0.25=1;(4) 178.8+ ( 26.45.6) =178.8+ 20.8=.17.【解答】 解：(1) 3.6 1.28+3.09=2.32+3.09=5.41(2)3.82+2.9+0.18+9.1 =(3.82+0.

33、18)+ (9.1+2.9)=4+12=16 (3) 9.43- (6.28- 1.57) =9.43+1.57- 6.28=11-6.28=4.72(4) 21.32- (6.32+8.3)=21.32- 6.32 - 8.3=15- 8.3=6.7 (5) 13.75- (3.75+6.48) =13.75- 3.75-6.48=10 -6.48=3.52 (6) 15- 7.35-2.65=15- (7.35+2.65) =15- 10=5 18.【解答】 解： 19.81 - 2.68- 8.32=19.81- (2.68+8.32) =19.81 - 11=8.81 5.6+6.6

34、- 5.6+6.6= (5.6-5.6) + (6.6+6.6) =0+13.2=13.20.81 X 27+0.19X27=27X (0.81+0.19)=27X 1=27 101 X0.19-0.19= (1011) X0.19=100X 0.19=19 19.【解答】 解： (1 ) 9.08 - 1.76 - 4.24 =9.08 -( 1.76+4.24 ) =9.08 - 6=3.08 ;(2) 18.38- (5.38+1.8) - 8.2=18.38- 7.18- 8.2=11.2- 8.2=3; (3) 17.45- (8.76 6.55) =17.45- 8.76+6.55

35、=17.45+6.55- 8.76=24- 8.76=15.24; (4) 12.87+3.98- 3.87=12.87- 3.87+3.98=9+3.98=12.98.20.【解答】解： 10.8+ (3.94+6.86)X0.8=10.8+ 10.8X0.8=1X0.8=0.80.65X201=0.65X (200+1) =0.65X 200+0.65 X 1=130+0.65=130.6巡 12.5X3.9X 0.8=12.5X 0.8X 3.9=10X 3.9=3939.8X0.25X4 =39.8X ( 0.25X4) =39.8X 1=39.8 37.6X 8+37.6X 2=37

36、.6X(8+2) =37.6 X 10=376 0.78X 99+0.78=0.78X ( 99+1 ) =0.78 X 100=7821.【解答】 解：(1) 21.8-7.22-2.78=21.8- (7.22+2.78) =21.8- 10=11.8 (2) 9-0.24-1.6X 1.1=9- 0.15X 1.1=9- 0.165=8.835 (3) 9.12+9.12X9-6.02=9.12 X ( 1+9) 6.02=9.12X 10 6.02=91.2 6.02=85.18 (4) 45.2 X 66.7+66.7 X 53.8+66.7= (45.2+53.8+1) X 66.

37、7=100X66.7=6670 (5) 0.25X0.8X0.125X0.4= (0.25X0.4) X (0.125X0.8)=0.1X0.1=0.01(6) 12.75+ 14.6- (1.3+8.2) =12.75 + 14.6-9.5 =12.75+5.1=2.5 (7) 0.125X36X (4 + 0.5) +36=0.125X (4+0.5) X (36+36) =0.125X 8X1=1 (8) (6.14.6) X0.8- 1 X 0.36= 1.5X 0.8 - 1 X 0.36= 1.21 X 0.36=0.2X0.36=0.072 (9) 15.6 (4.1+0.2+6

38、.86+ 0.7) =15.6 -(4.1+0.2+9.8) =15.5- (4.1+10) =15.5- 14.1=1.4 (10) 5- (1-1.2X0.8) + 4=5 (1 0.96) +4= 50.04 +4=4.96 + 4=1.24 ( 11) 1 +0.25+0.4 X 0.6=4+0.24=4.24 (12) 13.6X3 40.6+ 2=40.8 20.3=20.5 (13) 25.8+10.5+ ( 5-3.5) =25.8+10.5- 1.5=25.8+7=32.8 (14) 1.42- 0.36-6X0.6=1.42-0.36=1.07 (15 ) 49.5 義 0

39、.2 - 2.07 + 23=9.9 - 0.09=9.81 ( 16 ) 6.7+3.3 +4.4+5.6=6.7+0.75+5.6=7.45+5.6=13.05 22.【解答】 解： 50X (0.8+0.4) =50X 0.8+50 X 0.4=40+20=60 7.34 X 2.1+7.34X 6.8+7.34X 1.1=7.34X ( 2.1+6.8+1.1) =7.34 義 10=73.4 20.5 + 1.25 + 0.8=20.5 + ( 1.25 X 0.8 ) =20.5 + 1=20.5 9.88X9+9.88=9.88X ( 9+1) =9.88X 10=98.8 23

40、.【解答】 解：(1) 12.6 +(1.02+3.18) =12.6+ 4.2=3; (2) 5.7X6.9+4.3X 6.9= (5.7+4.3) X6.9=10X 6.9=69;(3) (0.81+2.7) +0.9=3.51+0.9=3.9; (4) (8.4 7.9) +0.25 X 1.2= 0.5+0.25X1.2=2X 1.2=24 24.【解答】 解：(1) 25X 1.25X32 =25X 1.25X8X4= (25X4) X (1.25X8) =100X10=1000 (2)(三*)X 35= X 35+1- X 35=10+7=17(3) 78 X(79-1) X79=

41、79X25.【解答】解：(1) 1.6X3.9X 1.25=0.8X2X3.9X 1.25= (0.8X 1.25)X (2X3.9) =1X7.8=7.8(2) 4.87X2.34+48.7X0.266=4.87X2.34+4.87X2.66=4.87 義(2.34+2.66) =4.87X 5=24.35 (3) 0.49X9.9 =0.49X ( 10- 0.1) =0.49X10- 0.49X0.1=4.9- 0.049=4.851 (4) 0.05X 0.7X20X 1.7= (0.05X20)義(0.7X1.7) =1X1.19=1.19 (5) 2.5X3.2X12.5 =2.5

42、X0.4X8X12.5 = (2.5X0.4)義(8X12.5) =1X100=100(6) 3.95X7.6+3.95X3.4-3.95=3.95X (7.6+3.4- 1) =3.95X10=39.5 26.【解答】 解：(1) 7.8X6.9+2.2X6.9= (7.8+2.2) X 6.9=10X 6.9=69 (2) 2.36 X2.5X4=2.36X (2.5X4) =2.36X10=23.6 (3) 102X0.45= (100+2) X 0.45=100 X 0.45+2X 0.45=45+0.9=45.9 (4) 4.19X 99+4.19=4.19X (99+1) =4.1

43、9X 100=419 (5)21.36+0.8 12.9=26.7 12.9=13.8(6)3.2-0.8X0.26=4X0.26=1.04 27.【解 答】解：(1) 6.33X101 6.33=6.33X (101 - 1) =6.33X100=633; (2) 1.6X55.4 -55.4 X 0.6= ( 1.6 - 0.6)義 55.4=1 義 55.4=55.4; ( 3) 17.68 + 5.2+2.7 義 1.5=3.4+4.05=7.45; (4) (1.1-0.78)義(2.7- 1.95) =0.32X0.75=0.24; (5) 35.6 -5 X 1.73=35.6

44、- 8.65=26.95; (6) 15 + 0.2+2.5=15+ ( 0.2 X 2.5) =15 +0.5=30.28.【解答】 解：(1) 2.5X 1.37X 0.4=2.5X 0.4X 1.37=1X 1.37=1.37;(2) 4.8X0.25X25= (4X4X0.3) X 0.25X25= (4X0.25)義(4X25) X 0.3=1 X 100X 0.3=30; (3) 0.89X 4.8+0.89X5.2=0.89X (4.8+5.2) =0.89X 10=8.9; (4) 101 X0.78X20=101 X (0.78X20) =101X15.6=(100+1) X

45、 15.6=100X 15.6+1 X 15.6=1560+15.6=1575.6; (5) 8.8X 1.25X 15= (8X1.1) X 1.25X15= (8X1.25) 義(1.1X15) =10X16.5=165; (6) 4.3 X 0.8 X 5=4.3 X (0.8X5) =4.3 X 4=17.2,29.【解答】 解：(1) 44.28+0.9 + 4.1=49.2+4.1=12; (2) 0.25X0.39X4= (0.25X4) X 0.39=1 X 0.39=0.39; (3) 7.6+7.6 X 99=7.6 X ( 1+99) =7.6X 100=760; (4)

46、 9.07-22.78+3.4=9.07 6.7=2.37; (5) 4.8X 99+4.8=4.8X (99+1) =4.8 義 100=480 ; ( 6 ) 6.3 X 10.1=6.3 義(10+0.1 ) =6.3 義 10+6.3 義 0.1=63+0.63=63.63.30.【解答】 解：(1) 5.8+3.8X 0.25=5.8+0.95=6.75 (2) 1.7義(4.65- 3.87) =1.7X 0.78=1.326 (3) 1.25X4.3X 0.8=1.25X 0.8X 4.3=1 X 4.3=4.3(4) 4.5X 102=4.5X ( 100+2) =4.5X 1

47、00+4.5X2=450+9=459 (5) 0.54X 101 - 0.54=0.54X (101- 1) =0.54X 100=54 (6) 3.4X 2.5+6.6X 2.5= (3.4+6.6) X 2.5=10 X 2.5=25 31.【解答】 解： 0.45X12X0.2=0.45X0.2X12=0.09X 12=1.08 6.2X2.1 -2.1 =2.1 X (6.2- 1) =2.1X5.2=10.92 0.9X 0.8X 100=0.72X 100=72 2.8 - 2.8 X 0.15 =2.8 X ( 1 - 0.15) =2.8 X 0.85=2.38 2.8 X 1

48、.43+0.57 =4.004+0.57=4.574 72 X 0.81+10.3=58.32+10.3=68.62 10-6.06+8.5=3.94+8.5=12.44 6X 0.25 X 1.8 =1.5 X 1.8=2.7 7.06 X 2.4 - 5.8=16.944-5.8=11.144 32.【解答】解：(1) 0.25X 9.87X4=0.25X4X9.87=1X 9.87=9.87; (2) 36.2X 1.8+13.8X 1.8= (36.2+13.8) X 1.8=50X 1.8=90;(3)0.125X2.3X8=0.125X8X2.3=1X2.3=2.3; (4)0.7

49、3X102 =0.73X (100+2) =0.73 X 100+0.73X 2=73+1.46=74.46;(5) (6.8+2.6) X 5 =6.8X 5+2.6X5=34+13=47;(6) 0.23X 98=0.23X ( 100-2) =0.23X 100-0.23X2=23- 0.46=22.54.33.【解答】 解：(1) 12.5X32X2.5 =12.5X 4X 8X2.5=(12.5X8)義(2.5X4) =100X10=1000；(2) 6.8X9.9=6.8X (10-0.1)=6.8X 10- 6.8X 0.1=68- 0.68=67.32;(3) 7.2+ 1.8

50、X (3.4- 2.9) =7.2一 1.8X0.5 =7.2+ 0.9=8.34.【解答】 解：(1) 3.4X9+3.4=30.6+3.4=34; (2)6.4+ 0.8- 1.5X4=8-6=2; (3) 3.78+ 0.25+4=3.78+ (0.25X4) =3.78+ 1=3.78;(4) 17+ (1.2+0.5) X5=17+ 1.7X5 =17+ 8.5=2.35.【解答】 解：(1)2.5X 1.25X8X0.4= (2.5X0.4)義(1.25X 8)=1X10=10； 12.8 X 1.7+87.2X 1.7=( 12.8+87.2) X 1.7=100X 1.7=17

51、0; ( 3) 100- 4.35 - 5.65=100-(4.35+5.65) =100 10=90.36.【解答】 解：(1) 4+7.6X15 =4+114=118; (2)26.08+0.25+ 4=26.08+ (0.25X4) =26.08+ 1=26.08; (3) 19.7+ (80.5+ 35X0.2) =19.7+ (2.3X0.2) =19.7+0.46=20.16.37.【解答】解：(1) 1.25X2.25X0.8=1.25X0.8X 2.25=1X2.25=2.25; (2) 9.7X 99+9.7=9.7X (99+1) =9.7X100=970; (3) 4.8

52、X7.8+78X0.52=4.8X7.8+7.8X5.2= (4.8+5.2) X 7.8=10X7.8=78; (4) 3.65X 10.1=3.65X (10+0.1) =3.65X 10+3.65X 0.1=36.5+0.365=36.865.38.【解答】解： 12.366.49 3.51=12.36 (6.49+3.51) =12.36- 10=2.36;8.5X 3.8+8.5 X6.2=8.5X (3.8+6.2) =8.5X 10=85; 17.3X 0.25X 8=17.3X ( 0.25X8) =17.3 X 2=34.6; 15.32- 1.8X5- 3.46=15.32

53、- 9-3.46=6.32- 3.46=2.86; 199X2.6=(200- 1) X2.6=200X 2.6- 1 X2.6=520-2.6=517.4;3.6+ (1.3+0.6) X 5 =3.6 一 1.9X5 =3.6+ 9.5萼. 39.【解答】 解：(1) 8.5+6.85-6.35 =8.5+ (6.85-6.35) =8.5+0.5=9; (2) 3.9+0.1 - 3.9+0.1 = (3.93.9) + (0.1+0.1) =0+0,2=0.2;(3) 12.6- (3.75+5.08) =12.6-8.83=3.77.40.【解答】 解：(1) 6.09-9.13+

54、8.3=6.09- 1.1=4.99 (2) 3.84X9.6+0.96X61.6 = (3.84+6.16) X9.6=10X 9.6=96(3) 4.86X99=4.86X (100- 1) =4.86X 100-4.86=486- 4.86=481.14 (4) 5.68 X 4+4.32- 0.25 =5.68X4+4.32X4= (5.68+4.32) X 4=10X4=40 (5) 6.4X 4.5+3.6 義 4.5= ( 6.4+3.6 )義 4.5=10 義 4.5=4541 .【解答】 解： 10.5+61 義18=10.5+1098=1108.5(3.14+12.6) + 8=15.74+ 8=1.967巡4.5+ (15+3) =4.5+ 5=0.975+448-4X 19=75+112X 19=75+2128=2203 42.【解 答】 解：(1) (18.5X3.8+3.8X2.5) +0.19 =3.8X (18.5+2.5) +0.19 =3.8X 21 + 0.19=3.8+0.19X21=200X 21=4200 (2) 32- ( 7.25+0.75X 8) + 50= 32 -(7.25+6) +50=32- 13.25+50=1