小数除法脱式运算+简算260道 含问题详解

小数除法脱式运算+简算260道一．计算题（共50小题）1．用你喜欢的方法计算．32×12.5×0.25 6.1×4.2+5.8×6.1 1.7÷2.5÷0.416.1﹣4.2﹣5.8．3．脱式计算4.8÷（1.2÷0.5）12.8﹣12.8÷571.4÷（7×6）4．用你喜欢的方法计算0.65×101﹣0.65 12.6﹣3.25+6.756.35÷0.2÷0.5 5.7×1.2÷19 1.25×3.63×0.8．5．我能用喜欢的方法计算下面各题．0.11×1.8+8.2×0.11 3.5﹣3.5×0.980.75×18÷0.150.25×4.78×8．6．能简算的要简算．17.3÷0.125÷8 14.72×0.7+5.28×0.73.5÷0.56 8.5×9.9+0.82．7．递等式计算，有简便运算的用简便方法38.75﹣（24.5+8.75）0.4×2.32×0.250.75×101 4.2﹣3.2×0.97.56×99+7.5670.3﹣17.48÷7.6 3.64÷5.2×23.321.8÷0.8﹣1.2×5 45÷（5.25÷0.25）16.5×101﹣16.50.96÷0.3×14 1.25×4×2.5×836.45÷（0.82+3.4×0.2）9.07﹣2.64÷0.4 1.5×10112.6×7.5+8.3 13.6×0.85﹣3.6×0.85104×8.586.4÷6.4﹣0.40.25×6.2×0.423×6.5+17×6.536÷0.4×0.25（24.6﹣18.1）×3.47.6×9.9+7.6×0.1 13.6×0.8×12.523.9×8.5﹣3.9×8.5（2.55+9.6÷16）÷0.429.2÷0.25÷48．脱式计算（能简算的要简算）0.75×4×0.25×49.6+9.9×9915.58÷8.2﹣0.724.536÷0.8÷14 2.8×3.6+1.4×2.8 6.3×10.1．9．脱式计算（能简算的要用简算）4.2×7.8+2.2×4.2 9.5×101（8×3.82）×1.250.125×720.6×3.9×0.8 42×0.39+4.2×6.110．脱式计算，能简算的要简算0.25×1.25×1618.9﹣18.9÷1.48.37×1.2﹣8.37×0.243×11.8+5.7×118．11．用简便方法计算．6.2+5.18+2.8 15.35﹣（5.35+7.2）3.63﹣1.25+17.37﹣8.75 51.72﹣8.66﹣1.34．12．脱式计算，能简算的要简算．0.7×101﹣0.7 0.125×4.95×8 12.9﹣1.68﹣2.32 567÷20÷5．13．用递等式计算，能简算的要简算．20.16÷7.2+9.8 6.2×2.7+6.5×7.3 32.8+9.6+7.2．14．脱式计算：能简算的要简算15.89﹣（5.89+6.98）0.25×13.7×0.432.7×28+7.3×2815×9.4﹣42 4.9+12.87﹣5.380.05×0.7×20×1.7．15．计算下面各题，能简算的要简算．5.04×28（15.4﹣7.8）×3.5 3.2×4.6+3.2×5.40.25×17.4×4 20﹣6.72﹣3.28 8.33+7.45+1.67+2.5516．脱式计算．0.2×0.6×0.5×4 （7.5﹣2.3×0.4）÷0.011.2×0.25+2.8×0.25 178.8÷（26.4﹣5.6）17．能简算的要简算3.6﹣1.28+3.09 3.82+2.9+0.18+9.1 9.43﹣（6.28﹣1.57）21.32﹣（6.32+8.3）13.75﹣（3.75+6.48）15﹣7.35﹣2.6518．混合运算，能简便就简便19.81﹣2.68﹣8.32 5.6+6.6﹣5.6+6.60.81×27+0.19×27101×0.19﹣0.19．19．用简便方法计算9.08﹣1.76﹣4.24 18.38﹣（5.38+1.8）﹣8.217.45﹣（8.76﹣6.55）12.87+3.98﹣3.87．20．脱式计算，能简便的用简便方法计算．10.8÷（3.94+6.86）×0.80.65×201 12.5×3.9×0.839.8×0.25×4 37.6×8+37.6×20.78×99+0.78．21．脱式计算：21.8﹣7.22﹣2.789﹣0.24÷1.6×1.19.12+9.12×9﹣6.0245.2×66.7+66.7×53.8+66.70.25×0.8×0.125×0.412.75÷[14.6﹣（1.3+8.2）] 0.125×36×（4÷0.5）÷36[（6.1﹣4.6）×0.8﹣1]×0.3615.6﹣（4.1+0.2+6.86÷0.7）[5﹣（1﹣1.2×0.8）]÷41÷0.25+0.4×0.613.6×3﹣40.6÷225.8+10.5÷（5﹣3.5） 1.42﹣0.36÷6×0.649.5×0.2﹣2.07÷236.7+3.3÷4.4+5.622．计算下面各题（能简算的要简算）50×（0.8+0.4）7.34×2.1+7.34×6.8+7.34×1.120.5÷1.25÷0.8 9.88×9+9.88．23．计算下列各题（能用简便算法的要用简便算法）．12.6÷（1.02+3.18） 5.7×6.9+4.3×6.9（0.81+2.7）÷0.9[（8.4﹣7.9）÷0.25]×1.2．25．能简算的用简便方法计算．（写出主要简便过程，无过程不得分）1.6×3.9×1.25 4.87×2.34+48.7×0.2660.49×9.9 0.05×0.7×20×1.72.5×3.2×12.5 3.95×7.6+3.95×3.4﹣3.95．26．计算下面各题，能简算的要简算7.8×6.9+2.2×6.9 2.36×2.5×4102×0.454.19×99+4.1921.36÷0.8﹣12.9 3.2÷0.8×0.2627．计算（能简算的要简算）．6.33×101﹣6.33 1.6×55.4﹣55.4×0.617.68÷5.2+2.7×1.5（1.1﹣0.78）×（2.7﹣1.95）35.6﹣5×1.7315÷0.2÷2.528．脱式计算（能简算的要简算）2.5×1.37×0.4 4.8×0.25×250.89×4.8+0.89×5.2101×0.78×208.8×1.25×15 4.3×0.8×529．计算下面各题，能简算的要简算．44.28÷0.9÷4.10.25×0.39×47.6+7.6×999.07﹣22.78÷3.4 4.8×99+4.8 6.3×10.130．下面各题，能简算的就要简算．5.8+3.8×0.25 1.7×（4.65﹣3.87） 1.25×4.3×0.84.5×1020.54×101﹣0.54 3.4×2.5+6.6×2.5．31．计算下列各题．0.45×12×0.2 6.2×2.1﹣2.1 0.9×0.8×1002.8﹣2.8×0.15 2.8×1.43+0.57 72×0.81+10.310﹣6.06+8.56×0.25×1.8 7.06×2.4﹣5.832．用简便方法计算．0.25×9.87×4 36.2×1.8+13.8×1.8 0.125×2.3×80.73×102 （6.8+2.6）×5 0.23×98．33．能用简便方法的用简便方法计算12.5×32×2.5 6.8×9.9 7.2÷[1.8×（3.4﹣2.9）]．34．用你喜欢的方法计算．3.4×9+3.4 6.4÷0.8﹣1.5×4 3.78÷0.25÷4 17÷[（1.2+0.5）×5]．35．用你喜欢的方法计算2.5×1.25×8×0.4 12.8×1.7+87.2×1.7 100﹣4.35﹣5.65．36．用递等式计算（能简算的要简算）．4+7.6×15 26.08÷0.25÷419.7+（80.5÷35×0.2）37．计算，能简算的要简算．1.25×2.25×0.8 9.7×99+9.7 4.8×7.8+78×0.523.65×10.1．38．计算下面各题．（能简算的用简便算法）①12.36﹣6.49﹣3.51②8.5×3.8+8.5×6.2③17.3×0.25×8④15.32﹣1.8×5﹣3.46⑤199×2.6⑥3.6÷[（1.3+0.6）×5] 39．计算8.5+6.85﹣6.35 3.9+0.1﹣3.9+0.1 12.6﹣（3.75+5.08）40．计算，能简算的要简算6.09﹣9.13÷8.3 3.84×9.6+0.96×61.6 4.86×995.68×4+4.32÷0.256.4×4.5+3.6×4.5．41．脱式计算．10.5+61×18 （3.14+12.6）÷8 4.5÷（15÷3）75+448÷4×19．42．计算：（18.5×3.8+3.8×2.5）÷0.19 [32﹣（7.25+0.75×8）]÷50．43．脱式计算，能简算的就简算：25.32﹣（3.4﹣1.2）12﹣0.62﹣4.38．44．用简便方法计算下面各题．5.12+2.54+4.8812.5×17.8×0.8 0.24×0.48×49.9×2.59.4×5.8+10.6×5.8 0.66×101 4.8×0.25 2.33×0.5×41.3×2.5+0.7×2.5 1.26×0.6+1.26×0.4 102×0.55 0.034×0.5×0.245．计算．（怎样简便就怎么计算）13.38+0.98=7.02﹣2.98 6.57﹣（0.68﹣0.39+0.32）13.8÷（1.38×0.2）30.7﹣0.12×2﹣0.76 7.8×1.0118.4﹣6.5+1.6+3.5 7.8÷0.6+7.8÷0.412.13+7.5﹣1.13+2.850.125×8.89.4×3.2+6×0.32 9.6×3.6+7.2×0.2．46．计算下面各题，能简算得要简算．96÷（100×0.48） 3.6÷（1.2+0.5）×6（967﹣31）÷（17+48）72×10.1+27×10.1．47．用自己喜欢的方法计算．3.4×7.8÷3.9 54÷（6.86+3.94）48．用简便方法计算0.486+0.01+3.99 17.5×2.3﹣7.5×2.3 1.25×11×4×0.8 4.8×39+61×4.8 45.55﹣（6.82+15.55） 3.2×99+3.22.5×56+4.5×56 （31.6﹣11.7）÷2.5÷43.6×0.9+3.6×0.149．计算下列各题．（能简算的要简算）7.5﹣2.4÷0.8×2.5 12.5×17+83×12.5399×2.5 25÷（2.5÷0.4）3.25×67+5.75×67+67 230÷2.5×7.5 6.3+0.84+3.7+8.16 100﹣（2.72+10.8）÷0.250．脱式计算0.25×3.25×4 6.72+3.2÷2.521.36÷0.4﹣23.40.8×4.5+1.2×4.5．小数除法脱式运算+简算260道参考答案与试题解析一．计算题（共50小题）1．【解答】解：（1）32×12.5×0.25=4×8×12.5×0.25=（4×0.25）×（8×12.5）=1×100=100（2）6.1×4.2+5.8×6.1=6.1×（4.2+5.8）=6.1×10=61（3）1.7÷2.5÷0.4=1.7÷（2.5×0.4）=1.7÷1=1.7（4）16.1﹣4.2﹣5.8=16.1﹣（4.2+5.8）=16.1﹣10=6.12．【解答】解：（1）（0.6×0.8+0.12）÷1.2=0.6÷1.2=0.5答：商是0.5．（2）（14.81+5.19）×（14.81﹣5.19）=20×9.62=192.4答：积是192.4．（3）[（2.7+4.5）÷12]×0.3=[7.2÷12]×0.3=0.6×0.3=0.18答：积是0.18．3．【解答】解：①4.8÷（1.2÷0.5）=4.8÷2.4=2②12.8﹣12.8÷5=12.8﹣2.56=10.24③71.4÷（7×6）=71.4÷7÷6=10.2÷6=1.74．【解答】解：①0.65×101﹣0.65 =0.65×（101﹣1）=0.65×100=65②12.6﹣3.25+6.75=12.6+（6.75﹣3.25）=12.6+3.5=16.1③6.35÷0.2÷0.5=6.35÷（0.2×0.5）=6.35÷0.1=63.5④5.7×1.2÷19 =5.7÷19×1.2=0.3×1.2=0.36⑤1.25×3.63×0.8=（1.25×0.8）×3.63=1×3.63=3.635．【解答】解：①0.11×1.8+8.2×0.11=0.11×（1.8+8.2）=0.11×10=1.1②3.5﹣3.5×0.98=3.5×（1﹣0.98）=3.5×0.02=0.07③0.75×18÷0.15=0.75÷0.15×18=5×18=90④0.25×4.78×8=0.25×8×4.78=2×4.78=9.566．【解答】解：①17.3÷0.125÷8 =17.3÷（0.125×8）=17.3÷1=17.3 ②14.72×0.7+5.28×0.7=（14.72+5.28）×0.7=20×0.7=14③3.5÷0.56 =（3.5÷0.7）÷（0.56÷0.7）=5÷8=0.625④8.5×9.9+0.82=8.5×（10﹣0.1）+0.82=8.5×10﹣8.5×0.1+0.82=85﹣0.85+0.82=85﹣（0.85﹣0.82）=85﹣0.03=84.977．【解答】解：（1）38.75﹣（24.5+8.75）=38.75﹣24.5﹣8.75=38.75﹣8.75﹣24.5=30﹣24.5=5.5；（2）0.4×2.32×0.25=0.4×0.25×2.32=0.1×2.32=0.232；（3）0.75×101=0.75×（100+1）=0.75×100+0.75×1=75+0.75=75.75；（4）4.2﹣3.2×0.9=4.2﹣2.88=1.32；（5）7.56×99+7.56=7.56×（99+1）=7.56×100=756；（6）70.3﹣17.48÷7.6=70.3﹣2.3=68；（7）3.64÷5.2×23.3=0.7×23.3=16.31；（8）21.8÷0.8﹣1.2×5=27.25﹣6=21.25；（9）45÷（5.25÷0.25）=45÷21=；（10）16.5×101﹣16.5=16.5×（101﹣1）=16.5×100=1650；（11）0.96÷0.3×14=3.2×14=44.8；（12）1.25×4×2.5×8=（1.25×8）×（4×2.5）=10×10=100；（13）36.45÷（0.82+3.4×0.2）=36.45÷（0.82+0.68）=36.45÷1.5=24.3；（14）9.07﹣2.64÷0.4=9.07﹣6.6=2.47；（15）1.5×101=1.5×（100+1）=1.5×100+1.5×1=150+1.5=151.5；（16）12.6×7.5+8.3=94.5+8.3=102.8；（17）13.6×0.85﹣3.6×0.85=（13.6﹣3.6）×0.85=10×0.85=8.5；（18）104×8.5=（100+4）×8.5=100×8.5+4×8.5=850+34=884；（19）86.4÷6.4﹣0.4=13.5﹣0.4=13.1；（20）0.25×6.2×0.4=0.25×0.4×6.2=0.1×6.2=0.62；（21）23×6.5+17×6.5=（23+17）×6.5=40×6.5=260；（22）36÷0.4×0.25=90×0.25=22.5；（23）（24.6﹣18.1）×3.4=6.5×3.4=22.1；（24）7.6×9.9+7.6×0.1=7.6×（9.9+0.1）=7.6×10=76；（25）13.6×0.8×12.5=13.6×（0.8×12.5）=13.6×10=136；（26）23.9×8.5﹣3.9×8.5=（23.9﹣3.9）×8.5=20×8.5=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÷（0.25×4）=9.2÷1=9.2．8．【解答】解：（1）0.75×4×0.25×4=（0.75×4）×（0.25×4）=3×1=3（2）9.6+9.9×99=9.6+9.9×（100﹣1）=9.6+9.9×100﹣9.9=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÷14=5.67÷14=0.405（5）2.8×3.6+1.4×2.8=2.8×（3.6+1.4）=2.8×5=14（6）6.3×10.1=6.3×（10+0.1）=6.3×10+6.3×0.1=63+0.63=63.639．【解答】解：（1）4.2×7.8+2.2×4.2 =4.2×（7.8+2.2 ）=4.2×10=42（2）9.5×101=9.5×（100+1）=9.5×100+9.5=950+9.5=959.5（3）（8×3.82）×1.25 =（8×1.25）×3.82=10×3.82=38.2（4）0.125×72=0.125×8×9=1×9=9（5）0.6×3.9×0.8 =2.34×0.8=1.872（6）42×0.39+4.2×6.1=42×0.39+42×0.61=42×（0.39+0.61）=42×1=42 10．【解答】解：（1）0.25×1.25×16=0.25×1.25×（2×8）=（0.25×2）×（1.25×8）=0.5×10=5（2）18.9﹣18.9÷1.4=18.9﹣13.5=5.4（3）8.37×1.2﹣8.37×0.2=8.37×（1.2﹣0.2）=8.37×1=8.37（4）43×11.8+5.7×118=43×11.8+57×11.8=（43+57）×11.8=100×11.8=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=41.7212．【解答】解：（1）0.7×101﹣0.7 =0.7×（101﹣1）=0.7×100=70（2）0.125×4.7×8=0.125×8×4.7=1×4.7=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÷（20×5）=567÷100=5.6713．【解答】解：①20.16÷7.2+9.8 =2.8+9.8=12.6；②6.2×2.7+6.5×7.3 =16.74+47.45=64.19；③32.8+9.6+7.2=9.6+（32.8+7.2）=9.6+40=49.6．14．【解答】解：（1）15.89﹣（5.89+6.98）=15.89﹣5.89﹣6.98=10﹣6.98=3.02；（2）0.25×13.7×0.4=0.25×0.4×13.7=0.1×13.7=1.37；（3）32.7×28+7.3×28 =（32.7+7.3）×28=40×28=1120；（4）15×9.4﹣42=141﹣42=99；（5）4.9+12.87﹣5.38=17.77﹣5.38=12.39；（6）0.05×0.7×20×1.7=0.05×20×0.7×1.7=1×0.7×1.7=0.7×1.7=1.19．15．【解答】解：（1）5.04×28=（5+0.04）×28=5×28+0.04×28=140+1.12=141.12；（2）（15.4﹣7.8）×3.5 =7.6×3.5 =26.6；（3）3.2×4.6+3.2×5.4=3.2×（4.6+5.4）=3.2×10=32；（4）0.25×17.4×4=0.25×4×17.4=1×17.4=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=8.33+1.67+7.45+2.55=（8.33+1.67）+（7.45+2.55）=10+10=20．16．【解答】解：（1）0.2×0.6×0.5×4 =（0.2×0.5）×（0.6×4）=0.1×2.4=0.24；（2）（7.5﹣2.3×0.4）÷0.01=（7.5﹣0.92）÷0.01=6.58÷0.01=658；（3）1.2×0.25+2.8×0.25 =（1.2+2.8）×0.25=4×0.25=1；（4）178.8÷（26.4﹣5.6）=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+0.18）+（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=518．【解答】解：①19.81﹣2.68﹣8.32=19.81﹣（2.68+8.32）=19.81﹣11=8.81②5.6+6.6﹣5.6+6.6=（5.6﹣5.6）+（6.6+6.6）=0+13.2=13.2③0.81×27+0.19×27=27×（0.81+0.19）=27×1=27④101×0.19﹣0.19=（101﹣1）×0.19=100×0.19=1919．【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=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：①10.8÷（3.94+6.86）×0.8=10.8÷10.8×0.8=1×0.8=0.8②0.65×201 =0.65×（200+1）=0.65×200+0.65×1=130+0.65=130.65③12.5×3.9×0.8=12.5×0.8×3.9=10×3.9=39④39.8×0.25×4 =39.8×（0.25×4）=39.8×1=39.8⑤37.6×8+37.6×2=37.6×（8+2）=37.6×10=376⑥0.78×99+0.78=0.78×（99+1）=0.78×100=78 21．【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÷1.6×1.1=9﹣0.15×1.1=9﹣0.165=8.835（3）9.12+9.12×9﹣6.02=9.12×（1+9）﹣6.02=9.12×10﹣6.02=91.2﹣6.02=85.18（4）45.2×66.7+66.7×53.8+66.7=（45.2+53.8+1）×66.7=100×66.7=6670（5）0.25×0.8×0.125×0.4=（0.25×0.4）×（0.125×0.8）=0.1×0.1=0.01（6）12.75÷[14.6﹣（1.3+8.2）]=12.75÷[14.6﹣9.5]=12.75÷5.1=2.5（7）0.125×36×（4÷0.5）÷36=0.125×（4÷0.5）×（36÷36）=0.125×8×1=1（8）[（6.1﹣4.6）×0.8﹣1]×0.36=[1.5×0.8﹣1]×0.36=[1.2﹣1]×0.36=0.2×0.36=0.072（9）15.6﹣（4.1+0.2+6.86÷0.7）=15.6﹣（4.1+0.2+9.8）=15.5﹣（4.1+10）=15.5﹣14.1=1.4（10）[5﹣（1﹣1.2×0.8）]÷4=[5﹣（1﹣0.96）]÷4=[5﹣0.04]÷4=4.96÷4=1.24（11）1÷0.25+0.4×0.6=4+0.24=4.24（12）13.6×3﹣40.6÷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÷6×0.6=1.42﹣0.36=1.07（15）49.5×0.2﹣ 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=13.0522．【解答】解：①50×（0.8+0.4）=50×0.8+50×0.4=40+20=60②7.34×2.1+7.34×6.8+7.34×1.1=7.34×（2.1+6.8+1.1）=7.34×10=73.4③20.5÷1.25÷0.8=20.5÷（1.25×0.8）=20.5÷1=20.5 ④9.88×9+9.88=9.88×（9+1）=9.88×10=98.823．【解答】解：（1）12.6÷（1.02+3.18）=12.6÷4.2=3；（2）5.7×6.9+4.3×6.9=（5.7+4.3）×6.9=10×6.9=69；（3）（0.81+2.7）÷0.9=3.51÷0.9=3.9；（4）[（8.4﹣7.9）÷0.25]×1.2=[0.5÷0.25]×1.2=2×1.2=2.4．24．【解答】解：（1）25×1.25×32 =25×1.25×8×4=（25×4）×（1.25×8）=100×10=1000（2）（+）×35=×35+×35=10+7=17（3）78×=（79﹣1）×=79×﹣=3﹣=2（4）÷+=÷=25．【解答】解：（1）1.6×3.9×1.25=0.8×2×3.9×1.25=（0.8×1.25）×（2×3.9）=1×7.8=7.8（2）4.87×2.34+48.7×0.266=4.87×2.34+4.87×2.66=4.87×（2.34+2.66）=4.87×5=24.35（3）0.49×9.9 =0.49×（10﹣0.1）=0.49×10﹣0.49×0.1=4.9﹣0.049=4.851（4）0.05×0.7×20×1.7=（0.05×20）×（0.7×1.7）=1×1.19=1.19（5）2.5×3.2×12.5 =2.5×0.4×8×12.5 =（2.5×0.4）×（8×12.5）=1×100=100（6）3.95×7.6+3.95×3.4﹣3.95=3.95×（7.6+3.4﹣1）=3.95×10=39.5 26．【解答】解：（1）7.8×6.9+2.2×6.9=（7.8+2.2）×6.9=10×6.9=69（2）2.36×2.5×4=2.36×（2.5×4）=2.36×10=23.6（3）102×0.45=（100+2）×0.45=100×0.45+2×0.45=45+0.9=45.9（4）4.19×99+4.19=4.19×（99+1）=4.19×100=419（5）21.36÷0.8﹣12.9=26.7﹣12.9=13.8（6）3.2÷0.8×0.26=4×0.26=1.0427．【解答】解：（1）6.33×101﹣6.33=6.33×（101﹣1）=6.33×100=633；（2）1.6×55.4﹣55.4×0.6=（1.6﹣0.6）×55.4=1×55.4=55.4；（3）17.68÷5.2+2.7×1.5=3.4+4.05=7.45；（4）（1.1﹣0.78）×（2.7﹣1.95）=0.32×0.75=0.24；（5）35.6﹣5×1.73=35.6﹣8.65=26.95；（6）15÷0.2÷2.5=15÷（0.2×2.5）=15÷0.5=30．28．【解答】解：（1）2.5×1.37×0.4=2.5×0.4×1.37=1×1.37=1.37；（2）4.8×0.25×25=（4×4×0.3）×0.25×25=（4×0.25）×（4×25）×0.3=1×100×0.3=30；（3）0.89×4.8+0.89×5.2=0.89×（4.8+5.2）=0.89×10=8.9；（4）101×0.78×20=101×（0.78×20）=101×15.6=（100+1）×15.6=100×15.6+1×15.6=1560+15.6=1575.6；（5）8.8×1.25×15=（8×1.1）×1.25×15=（8×1.25）×（1.1×15）=10×16.5=165；（6）4.3×0.8×5=4.3×（0.8×5）=4.3×4=17.2．29．【解答】解：（1）44.28÷0.9÷4.1=49.2÷4.1=12；（2）0.25×0.39×4=（0.25×4）×0.39=1×0.39=0.39；（3）7.6+7.6×99=7.6×（1+99）=7.6×100=760；（4）9.07﹣22.78÷3.4=9.07﹣6.7=2.37；（5）4.8×99+4.8=4.8×（99+1）=4.8×100=480；（6）6.3×10.1=6.3×（10+0.1）=6.3×10+6.3×0.1=63+0.63=63.63．30．【解答】解：（1）5.8+3.8×0.25=5.8+0.95=6.75（2）1.7×（4.65﹣3.87）=1.7×0.78=1.326（3）1.25×4.3×0.8=1.25×0.8×4.3=1×4.3=4.3（4）4.5×102=4.5×（100+2）=4.5×100+4.5×2=450+9=459（5）0.54×101﹣0.54=0.54×（101﹣1）=0.54×100=54（6）3.4×2.5+6.6×2.5=（3.4+6.6）×2.5=10×2.5=2531．【解答】解：①0.45×12×0.2=0.45×0.2×12=0.09×12=1.08②6.2×2.1﹣2.1 =2.1×（6.2﹣1）=2.1×5.2=10.92 ③0.9×0.8×100=0.72×100=72④2.8﹣2.8×0.15 =2.8×（1﹣0.15）=2.8×0.85=2.38 ⑤2.8×1.43+0.57 =4.004+0.57=4.574⑥72×0.81+10.3=58.32+10.3=68.62⑦10﹣6.06+8.5=3.94+8.5=12.44⑧6×0.25×1.8 =1.5×1.8=2.7⑨7.06×2.4﹣5.8 =16.944﹣5.8=11.14432．【解答】解：（1）0.25×9.87×4 =0.25×4×9.87=1×9.87=9.87；（2）36.2×1.8+13.8×1.8 =（36.2+13.8）×1.8=50×1.8=90；（3）0.125×2.3×8=0.125×8×2.3=1×2.3=2.3；（4）0.73×102 =0.73×（100+2）=0.73×100+0.73×2=73+1.46=74.46；（5）（6.8+2.6）×5 =6.8×5+2.6×5=34+13=47；（6）0.23×98=0.23×（100﹣2）=0.23×100﹣0.23×2=23﹣0.46=22.54．33．【解答】解：（1）12.5×32×2.5 =12.5×4×8×2.5=（12.5×8）×（2.5×4）=100×10=1000；（2）6.8×9.9 =6.8×（10﹣0.1）=6.8×10﹣6.8×0.1=68﹣0.68=67.32；（3）7.2÷[1.8×（3.4﹣2.9）]=7.2÷[1.8×0.5]=7.2÷0.9=8．34．【解答】解：（1）3.4×9+3.4=30.6+3.4=34；（2）6.4÷0.8﹣1.5×4=8﹣6=2；（3）3.78÷0.25÷4=3.78÷（0.25×4）=3.78÷1=3.78；（4）17÷[（1.2+0.5）×5]=17÷[1.7×5]=17÷8.5=2．35．【解答】解：（1）2.5×1.25×8×0.4 =（2.5×0.4）×（1.25×8）=1×10=10；（2）12.8×1.7+87.2×1.7 =（12.8+87.2）×1.7=100×1.7=170；（3）100﹣4.35﹣5.65=100﹣（4.35+5.65）=100﹣10=90．36．【解答】解：（1）4+7.6×15 =4+114=118；（2）26.08÷0.25÷4=26.08÷（0.25×4）=26.08÷1=26.08；（3）19.7+（80.5÷35×0.2）=19.7+（2.3×0.2）=19.7+0.46=20.16．37．【解答】解：（1）1.25×2.25×0.8=1.25×0.8×2.25=1×2.25=2.25；（2）9.7×99+9.7=9.7×（99+1）=9.7×100=970；（3）4.8×7.8+78×0.52=4.8×7.8+7.8×5.2=（4.8+5.2）×7.8=10×7.8=78；（4）3.65×10.1=3.65×（10+0.1）=3.65×10+3.65×0.1=36.5+0.365=36.865．38．【解答】解：①12.36﹣6.49﹣3.51=12.36﹣（6.49+3.51）=12.36﹣10=2.36；②8.5×3.8+8.5×6.2=8.5×（3.8+6.2）=8.5×10=85；③17.3×0.25×8=17.3×（0.25×8）=17.3×2=34.6；④15.32﹣1.8×5﹣3.46=15.32﹣9﹣3.46=6.32﹣3.46=2.86；⑤199×2.6=（200﹣1）×2.6=200×2.6﹣1×2.6=520﹣2.6=517.4；⑥3.6÷[（1.3+0.6）×5]=3.6÷[1.9×5]=3.6÷9.5=．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 =（3.9﹣3.9）+（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÷8.3=6.09﹣1.1=4.99（2）3.84×9.6+0.96×61.6 =（3.84+6.16）×9.6=10×9.6=96（3）4.86×99=4.86×（100﹣1）=4.86×100﹣4.86=486﹣4.86=481.14（4）5.68×4+4.32÷0.25 =5.68×4+4.32×4=（5.68+4.32）×4=10×4=40（5）6.4×4.5+3.6×4.5=（6.4+3.6）×4.5=10×4.5=4541．【解答】解：①10.5+61×18=10.5+1098=1108.5 ②（3.14+12.6）÷8=15.74÷8=1.9675③4.5÷（15÷3）=4.5÷5=0.9④75+448÷4×19=75+112×19=75+2128=220342．【解答】解：（1）（18.5×3.8+3.8×2.5）÷0.19 =3.8×（18.5+2.5）÷0.19 =3.8×21÷0.19=3.8÷0.19×21=200×21=4200（2）[32﹣（7.25+0.75×8）]÷50=[32﹣（7.25+6）]÷50=[32﹣13.25]÷50=18.75÷50=0.37543．【解答】解：①25.32﹣（3.4﹣1.2）=25.32﹣2.2=23.12②12﹣0.62﹣4.38=12﹣（0.62+4.38）=12﹣5=7 44．【解答】解：（1）5.12+2.54+4.88=5.12+4.88+2.54=10+2.54=12.54；（2）12.5×17.8×0.8=12.5×0.8×17.8=10×17.8=178；（3）0.24×0.48×4=0.1152×4=0.4608；（4）9.9×2.5=（10﹣0.1）×2.5=10×2.5﹣0.1×2.5=25﹣0.25=24.75；（5）9.4×5.8+10.6×5.8=（9.4+10.6）×5.8=20×5.8=116；（6）0.66×101=0.66×（100+1）=0.66×100+0.66×1=66+0.66=66.66；（7）4.8×0.25=（1.2×4）×0.25=1.2×（4×0.25）=1.2×1=1.2；（8）2.33×0.5×4 =2.33×（0.5×4）=2.33×2=4.66；（9）1.3×2.5+0.7×2.5=（1.3+0.7）×2.5=2×2.5=5；（10）1.26×0.6+1.26×0.4=1.26×（0.6+0.4）=1.26×1=1.26；（11）102×0.55=（100+2）×0.55=100×0.55+2×0.55=55+1.1=56.1；（12）0.034×0.5×0.2=0.034×（0.5×0.2）=0.034×0.1=0.0034．45．【解答】解：（1）13.38+0.98=13.38+（1﹣0.02）=13.38+1﹣0.02=14.38﹣0.02=14.36；（2）7.02﹣2.98 =7.02﹣（3﹣0.02）=7.02﹣3+0.02 =4.02+0.02=4.04；（3）6.57﹣（0.68﹣0.39+0.32）=6.57﹣（0.68+0.32﹣0.39）=6.57﹣（1﹣0.39）=6.57﹣0.61=5.96；（4）13.8÷（1.38×0.2）=13.8÷1.38÷0.2=10÷0.2=50；（5）30.7﹣0.12×2﹣0.76 =30.7﹣0.24﹣0.76=30.7﹣（0.24+0.76）=30.7﹣1=29.7；（6）7.8×1.01=7.8×（1+0.01）=7.8×1+7.8×0.01=7.8+0.078=7.878；（7）18.4﹣6.5+1.6+3.5 =（18.4+1.6）﹣（6.5﹣3.5）=20﹣3=17；（8）7.8÷0.6+7.8÷0.4=13+19.5=32.5；（9）12.13+7.5﹣1.13+2.85=（12.13﹣1.13）+（7.5+2.85）=11﹣10.35=0.65；（10）0.125×8.8=0.125×（8+0.8）=0.125×8+0.125×0.8=1+0.1=1.1；（11）9.4×3.2+6×0.32 =9.4×3.2+0.6×3.2=（9.4+0.6）×3.2=10×3.2=32；（12）9.6×3.6+7.2×0.2=9.6×3.6+3.6×2×0.2=9.6×3.6+3.6×0.4=（9.6+0.4）×3.6=10×3.6=36．46．【解答】解：（1）96÷（100×0.48）=96÷48=2；（2）3.6÷（1.2+0.5）×6=3.6÷1.7×6=×6=；（3）（967﹣31）÷（17+48）=936÷65=14.4；（4）72×10.1+27×10.1=（72+27）×10.1=99×10.1=99×（10+0.1）=99×10+99×0.1=990+9.9=999.9．47．【解答】解：（1）3.4×7.8÷3.9=26.52÷3.9=6.8；（2）54÷（3.94+6.86）=54÷10.8=5．48．【解答】解：①0.486+0.01+3.99 =0.486+（0.01+3.99）=0.486+4=4.486 ②17.5×2.3﹣7.5×2.3 =2.3×（17.5﹣7.5）=2.3×10=23 ③1.25×11×4×0.8=（1.25×0.8）×（11×4）=1×44=44④4.8×39+61×4.8=4.8×（39+61）=4.8×100=480 ⑤45.55﹣（6.82+15.55）=45.55﹣6.82﹣15.55=45.55﹣15.55﹣6.82=30﹣6.82=23.18⑥3.2×99+3.2=3.2×（99+1）=3.2×100=320⑦2.5×56+4.5×56 =56×（2.5+4.5）=56×7=392⑧（31.6﹣11.7）÷2.5÷4 =19.9÷（2.5×4）=19.9÷10=1.99⑨3.6×0.9+3.6×0.1=3.6×（0.9+0.1）=3.6×1=3.649．【解答】解：（1）7.5﹣2.4÷0.8×2.5 =7.5﹣3×2.5=7.5﹣7.5=0；（2）12.5×17+83×12.5=12.5×（17+83）=12.5×100=1250；（3）399×2.5 =（400﹣1）×2.5=400×2.5﹣2.5=1000﹣2.5=997.25；（4）25÷（2.5÷0.4）=25÷2.5×0.4=10×0.4=4；（5）3.25×67+5.75×67+67 =（3.25+5.75+1）×67=10×67=670；（6）230÷2.5×7.5=92×7.5=690；（7）6.3+0.84+3.7+8.16=（6.3+3.7）+（0.84+8.16）=10+9=19；（8）100﹣（2.72+10.8）÷0.2=100﹣13.52÷0.2=100﹣67.6=32.4．50．【解答】解：（1）0.25×3.25×4=0.25×4×3.25=1×3.25=3.25（2）6.72+3.2÷2.5=6.72+1.28=8（3）21.36÷0.4﹣23.4=53.4﹣23.4=30（4）0.8×4.5+1.2×4.5=（0.8+1.2）×4.5=2×4.5=9。