五年级数学上册《小数乘法》简便计算及口算

五年级数学上册《小数乘法》简便计算及口算

(1)8.2×99+8.2

=8.2×(99+1)

=8.2×100

=820

(2)8.8×12.5

=(8+0.8)×12.5

=100+10

=110

(3)12.5×3.4×0.8

=12.5×0.8×3.4

=10×3.4

=34

(4)16×12.5×4.3

=2×8×12.5×4.3

=(2×4.3)×(8×12.5)

=8.6×100

=860

(5)0.78×9.9

=0.78×(10-0.1)

=0.78×10-0.78×0.1

=7.8-0.078

=7.722

(6)0.34×101

=0.34×(100+1)

=0.34×100+0.34

=34+0.34

=34.34

(7)8.57×103-8.57×3

=8.57×(103-3)

=8.57×100

=857

(8)5×0.2×8×1.25

=(5×0.2)×(8×1.25)

=1×10

=10

(9)0.5×7.6×20

=(0.5×20)×7.6

=10×7.6

=76

(10)90.5×99+90.5

=90.5×(99+1)

=90.5×100

=9050

(11)0.25×16.2×4

=0.25×4×16.2

=1×16.2

=16.2

(12)1.25×3.2×0.8

=1.25×0.8×3.2

=1×3.2

=3.2

(13)3.78×0.8+3.78×0.2

=3.78×(0.8+0.2)

=3.78×1

=3.78

(14)7.09×10.8-0.8×7.09

=7.09×(10.8-0.8)

=7.09×10

=70.9

(15)8.37×1.4+8.6×8.37

=8.37×(1.4+8.6)

=8.37×10

=83.7

五年级数学上册《小数乘法》简便计算及口算

(16)4.5×13.6+55×1.36

=45×1.36+55×1.36

=(45+55)×1.36

=100×1.36

=136

(17)4.86×99

=4.86×(100-1)

=4.86×100-4.86

=486-4.86

=481.44

(18)0.43×102

=0.43×(100+2)

=0.43×100+0.43×2

=43+0.86

=43.86

(18)0.78×16.5-0.78×15.5

=0.78×(16.5-15.5)

=0.78×1

=0.78

(19)76×0.3+5.24×0.3+0.3

=0.3×(76+5.24+1)

=0.3×82.24

=24.672

(20)7.5×2.3+0.25×23

=2.3×(7.5+2.5)

=2.3×10

=23

(22)9.8×5.6+9.8×4.4

=9.8×(5.6+4.4)

=9.8×10

=98

(23)3.6×10.1

=3.6×(10+0.1)

=3.6×10+3.6×0.1

=36+0.36

=36.36

(24)76.1×17-76.1×7

=76.1×(17-7)

=76.1×10

=761

五年级数学上册《小数乘法》简便计算及口算

19×3.5＝66.5

1×17.4＝17.4

4.9×18.55＝90.895

2×12.5＝25

2×10.2＝20.4

2.3×14.27＝32.821

5×17.4＝87

4×19.5＝78

13.2×1.24＝16.368

2×9.9＝19.8

1×12.8＝12.8

4.27×20.5＝87.535

3×6.5＝19.5

0×20.2＝0

17.6×5.49＝96.624

11×6.8＝74.8

19×0.7＝13.3

6.5×11.16＝72.54

5×9.4＝47

3×14.7＝44.1

7.3×11.64＝84.972

10×5.4＝54

6×10.2＝61.2

3.49×5＝17.45

13×7.5＝97.5

9×2.8＝25.2

4.02×14.8＝59.496

10×7.6＝76

1×19.3＝19.3

12.48×3.9＝48.672

12×0.3＝3.6

3×17.6＝52.8

2.32×12.3＝28.536

7×0.5＝3.5

4×15.7＝62.8

3.4×0.32＝1.088

3×4.5＝13.5

3×17.5＝52.5

7.39×10.57＝78.1123

4×12.6＝50.4

8.2×2＝16.4

6.02×6.49＝39.0698

9.9×5＝49.5

0.7×18＝12.6

17.83×2.6＝46.358

17.2×4＝68.8

6.5×14＝91

0.94×18.82＝17.6908

2.1×17＝35.7

3.3×6＝19.8

3.13×2.41＝7.5433

3.5×20＝70

6.7×8＝53.6

5.61×5.14＝28.8354

2.3×17＝39.1

20.2×0＝0

19.9×3.21＝63.879

4.1×3＝12.3

16.4×4＝65.6

4.7×0.25＝1.175

13.6×4＝54.4

1.3×14＝18.2

3.12×3.91＝12.1992

五年级数学上册《小数乘法》简便计算及口算

3.2×14＝44.8

12.3×8＝98.4

2.22×15.07＝33.4554

8.2×7＝57.4

4.7×18＝84.6

12.88×3.05＝39.284

1.8×16＝28.8

10.9×2＝21.8

18.76×2.77＝51.9652

10.2×9＝91.8

0.4×9＝3.6

0.84×19.3＝16.212

5.1×12＝61.2

20.7×2＝41.4

4.3×17.86＝76.798

2.8×7＝19.6

8.6×11＝94.6

8.31×10.3＝85.593

3.7×13.7＝50.69

0.8×8.6＝6.88

11.2×6.4＝71.68

10.3×0.4＝4.12

5.6×4.9＝27.44

7.53×10.4＝78.312

1.1×18.6＝20.46

1×3.9＝3.9

7.71×10.6＝81.726

11.6×6＝69.6

0.9×2.3＝2.07

0.2×6.98＝1.396

9×10.5＝94.5

2.2×15.3＝33.66

6.85×10.7＝73.295

1.8×20.4＝36.72

1.3×13.2＝17.16

4.62×18.71＝86.4402

2.2×17.9＝39.38

7.3×11.9＝86.87

3.25×11.64＝37.83

18.8×3.4＝63.92

0.3×19.9＝5.97

5.45×4.46＝24.307

0.2×19.6＝3.92

9.6×4.8＝46.08

15.83×0.81＝12.8223

五年级数学上册《小数乘法》简便计算及口算

3.1×19.9＝61.69

2.5×12.4＝31

2.35×11.38＝26.743

8.6×6.9＝59.34

4.2×6.8＝28.56

5.94×10.84＝64.3896

12.6×1.4＝17.64

1.6×12.7＝20.32

1.61×11.89＝19.1429

14.5×2.4＝34.8

11.6×0.8＝9.28

7.71×5.57＝42.9447

1×11.3＝11.3

6×16.7＝100.2

1.86×19.73＝36.6978

6×9.6＝57.6

18×0.1＝1.8

19.86×4.33＝85.9938

5×9.5＝47.5

0.73×9.6＝7.008

3.84×6.39＝24.5376

10×7.3＝73

5.1×0.6＝3.06

14.77×6.83＝100.8791

3×14.1＝42.3

13.97×7＝97.79

8.5×10.86＝92.31

0×16.8＝0

7.1×1.4＝9.94

16.8×2.84＝47.712

4×13.4＝53.6

4.4×7.16＝31.504

20.4×4.43＝90.372

5×4.1＝20.5

16.3×0.45＝7.335

6.52×0.1＝0.652

4×8.4＝33.6

5.8×5.6＝32.48

1.8×16.65＝29.97

5×19.7＝98.5

2.5×9.65＝24.125

2.95×7.8＝23.01

3×6.1＝18.3

0.1×1.3＝0.13

0.18×8.4＝1.512

11.4×7＝79.8

4.9×8.8＝43.12

5.3×8.44＝44.732

7.9×5＝39.5

12.9×6.3＝81