计算下面各题,怎样简便就怎样算。
专训(一)
(1)27.3+73.2+72.7 (2)5.85-1.75-0.25
(3)15.047+8.92-5.047 (4)12.6-3.28+7.4-5.72
(5)7.8-3.5+2.2-6.5 (6)600÷[(160-76)÷7]
(7)70×4+90×4 (8)840÷35
(9)382×101-382 (10)12-1.56-0.44
专训(二)
(11)42-6.78-3.22 (12)27×53+47×27
(13)25×125×8 (14)(105-88)×(25+73)
(15)[180+19×(106+74)]÷60 (16) 40.65-(7.38+16.85)
(17)87×47+53×87 (18)73.72-(36.28+3.72)-
(19)[780÷(128-113)]×45 (20)210÷14÷5
专训(三)
(21)8.3+6.2+1.7 (22)(125+4)×8
(23)73.26-(18.9+3.26) (24)101×9.9
(25)832÷[(241-225)×4] (26)45×37+73×45-10×45
(27)51.27-8.66+1.34 (28)106×9+91×8
(29)1500÷25×4 (30)20-7.2-2.8
专训(四)
(31)75×99+75 (32)25×32×125
(33)876+497+224+403 (34)8.75-(4.75+2.36)
(35)25×(104-89-3) (36)125×25×(8×4)
(37)65.4×38+63×65.4-65.4 (38)1400÷25÷8
专训(一)
答案
(1) 27.3+73.2+72.7 (2)5.85-1.75-0.25
=27.3+72.7+73.2 =5.85-(1.75+0.25)
=100+73.2 =5.85-2
=173.2 =3.85
(3)15.047+8.92-5.047
=15.047-5.047+8.92
=10+8.92
=18.92
(4)12.6-3.28+7.4-5.72
=(12.6+7.4)-(3.28+5.72)
=20-9
=11
(5) 7.8-3.5+2.2-6.5
=7.8+2.2-(3.5+6.5)
=10-10
=0
(6)600÷[(160-76)÷7]
=600÷[84÷7]
=50
(7)70×4+90×4 (8)840÷35
=(70+90)×4 =840÷7÷5
=160×4 =120÷5
=640 =24
(9)382×101-382 (10)12-1.56-0.44
=382×(101-1) =12-(1.56+0.44)
=382×100 =12-2
=38200 =10
专训(二)答案
11)42-6.78-3.22
=42-(6.78+3.22)
=42-10
=32
(12)27×53+47×27
=27×(53+47)
=2700
(13)25×125×8
=25×(125×8)
=25×1000
=25000
(14)(105-88)×(25+73)
=17×98
=1666
(15)60 (16)16.42 (17)8700
(18)33.72 (19)2340 (20)3
专训(三)答案
(21)8.3+6.2+1.7
=8.3+1.7+6.2
=10+6.2
=16.2
(22)(125+4)×8
=125×8+4×8
=1032
(23)73.26-(18.9+3.26)
=73.26-3.26-18.9
=70-18.9
=51.1
(24)101×9.9
=(100+1)×9.9
=100×9.9+9.9
=990+9.9
=999.9
(25)832÷[(241-225)×4]
=832÷[16×4]
=832÷64
=13
(26)45×37+73×45-10×45
=45×(37+73-10)
=45×100
=4500
(27)51.27-8.66+1.34 (28)106×9+91×8
=42.61+1.34 =954+728
=43.95 =1682
(29)1500÷25×4 (30)20-7.2-2.8
=60×4 =20-(7.2+2.8)
=240 =10
专训(四)答案
(31)75×99+75 (32)25×32×125
=75×(99+1) =25×4×(8×125)
=7500 =100×1000
=100000
(33)876+497+224+403
=876+224+(497+403)
=1100+900
=2000
(34)8.75-(4.75+2.36)
=8.75-4.75-2.36
=4-2.36
=1.64
(35)25×(104-89-3) (36)125×25×(8×4)
=25×12 =125×8×(25×4)
=25×4×3 =1000×100
=300 =100000
(37)65.4×38+63×65.4-65.4
=65.4×(38+63-1)
=65.4×100
=6540
(38)1400÷25÷8
=1400÷(25×8)
=1400÷200
=7