苏教版五年级上册数学小数加减乘除简便计算（课件）(共10张PPT)

(共10张PPT)
简便计算
苏教版小学数学五年级上册
a - b- c = a-（b+c）
a -（ b+ c ）=a - b- c
a -（ b- c ）=a - b+ c
a +b=b+ a
（a +b）+ c=a +（ b+ c ）
加法交换律
加法结合律
减法的性质
加法和减法的简便运算
a ×b = b×a
（a ×b）× c=a ×（ b× c ）
乘法交换律
乘法结合律
除法的性质
a÷b÷c = a÷（b×c）
a÷（b×c）= a÷b÷c
乘法和除法的简便运算
（a + b）× c = a× c + b× c
a× c + b× c =（a + b）× c
乘法分配律
a÷（b÷c）= a÷b×c
同一级运算
含有加法和乘法两级运算
3.57-0.18+6.43-4.82 23.76-（4.87+3.76）
14.2-5.39-4.61 17.5-（7.5-8.25）
=（3.57+6.43）-（0.18+4.82）
= 10-5
= 5
= 23.76-3.76-4.87
= 20-4.87
= 15.13
= 14.2-（5.39+4.61）
= 14.2- 10
= 4.2
= 17.5-7.5+8.25
= 10+8.25
= 18.25
12.5×0.96×8 0.25×3.6
1.25×3.2×2.5
=12.5×8×0.96
=100×0.96
=96
=0.25×4×0.9
=1×0.9
=0.9
=1.25×8×0.4×2.5
=（1.25×8）×（0.4×2.5）
= 10×1
= 10
8.1÷（0.9×0.3）
（2.4+0.48）÷1.2
4.5÷1.8
（8.25-3.75）÷2.5÷4
7.32÷（7.32÷3.35）
= 8.1÷0.9÷0.3
= 9÷0.3
= 30
= 4.5÷2.5÷4
= 4.5÷（2.5×4）
= 4.5÷10
= 0.45
= 7.32÷7.32×3.35
= 1×3.35
= 3.35
= 4.5÷9÷0.2
= 0.5÷0.2
= 2.5
= 2.4÷1.2+0.48÷1.2
= 2+0.4
= 2.4
1.28×8.6 - 0.28×8.6
5.5×4.8+5.2×5.5
0.55×99+0.55
1.28×101-1.28
=（4.8+5.2）×5.5
= 10×5.5
= 55
=（1.28-0.28）×8.6
= 1×8.6
= 8.6
=（99+1）×0.55
= 100×0.55
= 55
=（101-1）×1.28
= 100×1.28
= 128
5.5×4.8 + 52×0.55
0.33×7 + 0.99
5.5×3.7+5.2×5.5+5.5×1.1
5.5÷0.1 + 52×10
=（3.7+5.2+1.1）×5.5
= 10×5.5
= 55
= 0.33×7+0.33×3
=（ 7+3 ）×0.33
= 10×0.33
= 3.3
= 5.5×4.8+5.2×5.5
=（4.8+5.2）×5.5
= 10×5.5
= 55
= 5.5×10+52×10
=（5.5+52）×10
= 57.5×10
= 575
16.8×10.1
4.5×0.99
0.25×4.4
0.4×（2.5+1.25）×8
= 16.8×（10+0.1）
= 16.8×10+16.8×0.1
= 168+1.68
= 169.68
= 4.5×（1-0.01）
= 4.5×1-4.5×0.01
= 4.5-0.045
= 4.455
= 0.25×（4+0.4）
= 0.25×4+0.25×0.4
= 1+0.1
= 1.1
= 0.4×2.5×8+0.4×1.25×8
= 8+4
= 12
=0.25×4×1.1
= 1×1.1
= 1.1