1. 846.7×5                            2.796.64×25

3. 69.47÷0.5                        4. 34.128÷0.25

5.0.99÷4.5                          6.4.8÷2.5

7.12.5×0.25×0.05×3.7×6.4         8..12.728÷2.5÷32÷0.125

9.0.04×0.5×1.25×0.8×0.2×0.025

10. 9.87÷28.6×4.59÷98.7×2.86÷45.9

11.5.6×16.5÷0.7÷1.1

12.（6.4×12.5×0.5）÷（2.5×1.6×0.2）

13.0.525×17.36÷13.125÷4

14.3700÷6.4÷2.5÷12.5÷0.5

小学五年级奥数—小数乘除法简算  巧算(answer)

1 846.7×5=846.7×10÷2=4233.5
2 796.64×25=796.64×100÷4=19916
3 69.47÷0.5=69.47÷10×20=138.94
4 34.128÷0.25=34.128÷10×40=3.1428×40=136.512
5 0.99÷4.5=（0.99÷9）÷（4.5÷9）=0.11÷0.5=0.22
6 4.8÷2.5=4.8÷10×4=0.48×4=1.92
7 12.5×0.25×0.05×3.7×6.4
=12.5×0.25×0.05×3.7×（0.8×8）
=12.5×0.8×0.25×0.05×3.7×0.8
=100×0.25×0.05×3.7×（0.4×2）
=100×(0.25×0.4)×(0.05×2)×3.7
=100×0.1×0.1×3.7
=3.7
8 12.725/2.5/32/0.125
=12.728÷2.5÷(4×8)÷0.125
=12.728÷(2.5×4)÷(0.125×8)
=12.728÷10÷1
=1.2728
9 0.04×0.5×1.25×0.8×0.2×0.025
=(0.04×0.5)×(1.25×0.8)×(0.2×0.025)
=0.02×1×0.005
=0.02×0.005
=0.0001
10 9.87÷28.6×4.59÷98.7×2.86÷45.9
=(9.87÷98.7)÷(28.6÷2.86)×(4.59÷45.9)
=0.1÷10×0.1
=0.01×0.1
=0.001
11 5.6×16.5×0.7÷1.1
=(5.6÷0.7)×(16.5÷1.1)
=8×15
=120
12 (6.4×12.5×0.5)÷(2.5×1.6×0.2)
=(6.4÷1.6)×(12.5÷2.5)×(0.5÷0.2)
=4×5×2.5
=20×2.5
=50
13 0.525×17.36÷13.125÷4
=912.45÷（13.125×4）
=912.45÷52.5
=0.1736
14 3700÷6.4÷2.5÷12.5÷0.5
=3700÷（8×0.8）÷2.5÷12.5÷0.5
=3700÷（12.5×8）÷2.5÷0.5÷0.8
=3700÷100÷2.5÷0.5÷(0.4×2)
=3700÷(12.5×8)÷(2.5×0.4)÷(0.5×2)
=3700÷100÷1÷1
=37