2.9*0.45+0.29*5.5简便演算法怎么做
2.9*0.45+0.29*5.5简便演算法怎么做
原式=(29 / 10)*(45 / 100)+(29 /100 )*(55 /10) = 29/10 * (45 / 100 + 55/100) = 2.9
2.9×0.45+0.29×5.5用简便方法计算
2.9×0.45+0.29×5.5
=0.29×4.5+0.29×5.5
=0.29×(4.5+5.5)
=0.29×10
=2.9
2.9*0.45+ 0.29*4.2 +0.029*13简便演算法
2.9*0.45+ 0.29*4.2 +0.029*13
=0.29*4.5+ 0.29*4.2 +0.29*1.3
=0.29*(4.5+4.2+1.3)
=0.29*10
=2.9
2.9×5.37+29×0.45+0.29×1.2简便计算
2.9×5.37+29×0.45+0.29×1.2
=2.9x（5.37+10x0.45+0.1x1.2）
=2.9x（5.37+4.5+0.12）
=2.9x（9.87+0.12）
=2.9x9.99
=2.9x（10-0.01）
=2.9x100-2.9x0.01
=290-0.029
=289.971
谢谢，请采纳
2.9*1.4 0.29*0.16简便演算法
2.9*1.4=3*1.4-0.1*1.4=4.2-0.14=4.06
0.29*1.6=0.3*1.6-0.01*1.6=0.48-0.016=0.464
应该都是因为29和3比较接近算的吧。
其实列一个竖式也不麻烦的。
3.8×2.9+0.29×62简便演算法
=3.8×2.9+0.29×10×6.2
=3.8×2.9+2.9×6.2
=2.9(3.8+6.2)
=2.9×10
=29
4.8×2.9+0.29+0.29的简便演算法是
4.8×2.9+0.29+0.29
=48x0.29+0.29+0.29
=（48+1+1）x0.29
=50x0.29
=14.5
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17.37×2.9+0.29×36.3-2.9的简便演算法
17.37×2.9+0.29×36.3-2.9
=17.37×2.9+0.29×10×3.63-2.9×1
=2.9×(17.37+3.63-1)
=2.9×20
=58
3.8×2.9+0.29×62的简便演算法
3.8×2.9+0.29×62
=3.8×2.9+2.9×6.2
==2.9×（3.8+6.2）
=2.9×10
=29
2.9*0.45+0.29*4.2+0.029*13怎么做?
=2.9*0.45+2.9*0.42+2.9*0.13
=2.9*(0.45+0.42+0.13)
=2.9*1
=2.9
