五年级上册数学《小数简便运算》计算题专项训练,吃透简便运算技巧 ~

1. 加法交换律简算

2. 加法结合律简算

0.75+9.8+0.25

48.8+0.4+0.6

=0.75+0.25+9.8

=48.8+(0.4+0.6)

=1+9.8

=10.8

=48.8+1

=49.8

3. 乘法交换律简算

4. 乘法结合律简算

2.5×5.6×0.4

99×12.5×0.8

=2.5×0.4×5.6

=99×(12.5×0.8)

=1×5.6

=5.6

=99×10

=990

5. 含加法交换律与结合律

6. 含乘法交换律与结合律

6.5+0.28+3.5+0.72

2.5×1.25×0.4×0.8

=6.5+3.5+0.28+0.72

=2.5×0.4×1.25×0.8

=(6.5+3.5)+(0.28+0.72)

=(2.5×0.4)×(1.25×0.8)

=10+1

=11

=1×1

=1

7. 乘法分配律

8. 乘法分配律

7.6×0.8+0.2×7.6

1.28×8.6+0.72×8.6

=7.6×(0.8+0.2)

=(1.28+0.72)×8.6

=7.6×1

=2×8.6

=7.6

=17.2

9. 乘法分配律提取式

10. 乘法分配律提取式

1.35×12-1.35×2

95.5÷1.6-15.5÷1.6

=1.35×(12-2)

=(95.5-15.5)÷1.6

=1.35×10

=80÷1.6

=13.5

=50

11. 因数换减法

12. 因数换加法

99×2.6

4.5×102

=(100-1)×2.6

=4.5×(100+2)

=100×2.6-1×2.6

=4.5×100+4.5×2

=260-2.6

=257.4

=450+9

=459

13. 乘法分配律(添加因数“1”)

99×25.6+25.6

3.5×8+3.5×3-3.5

=99×25.6+1×25.6

=3.5×8+3.5×3-3.5×1

=(99+1)×25.6

=3.5×(8+3-1)

=100×25.6

=2560

=3.5×10

=35

14. 减法的性质简算例子

15. 减法的性质简算例子

52.8-6.5-3.5

5.28-0.89-1.28

=52.8-(6.5+3.5)

=5.28-1.28-0.89

=52.8-10

=42.8

=4-0.89

=3.11

16. 减法的性质简算例子

17. 因数换乘法

5.28-(1.5+1.28)

0.56×125

=5.28-1.28-1.5

=0.7×0.8×125

=4-1.5

=2.5

=0.7×(0.8×125)

=70

2.56-0.58+0.44

2.5÷0.8×0.4

=2.56+0.44-0.58

=2.5×0.4÷0.8

=3-0.58

=2.42

=1÷0.8

=1.25

5.88+1.62-0.88

290×2.5÷0.29

=5.88-0.88+1.62

=290÷0.29×2.5

=5+1.62

=6.62

=1000×2.5

=2500