五年级数学题!怎么做！

来源：百度知道编辑：UC知道时间：2024/06/16 08:54:38

使用简便方法计算！
1：3.25*3.8+32.5*0.72

2:4.5*98+9

您好！

1.
3.25*3.8+32.5*0.72
=32.5*0.38+32.8*0.72
=32.5*(0.38+0.72)
=32.5*1.1
=35.75

2.
4.5*98+9
=4.5*98+4.5*2
=4.5*(98+2)
=4.5*100
=450

1、原式=32.5*0.38+32.5*0.72=32.5*(0.38+0.72)=32.5
2、原式=4.5*(100-2)+9=450-9+9=450

1 3.25*3.8+32.5*0.72=3.25*3.8+3.25*7.2=3.25*(3.8+7.2)=3.25*11=35.75
2 4.5*98+9=9*49+9=9*(49+1)=9*50=450

3.25*3.8+32.5*0.72
=3.25*3.8+3.25*0.72*10
=3.25*3.8+3.25*7.2
=3.25*(3.8+7.2)
=35.75

4.5*98+9
=4.5*(100-2)+4.5*2
=450-4.5*2+4.5*2
=450

3.25*3.8+32.5*0.72
=3.25*3.8+3.25*7.2
=3.25(3.8+7.2)
=3.25*11
=35.75

4.5*98+9
=4.5*98+4.5*2
=4.5(98+2)
=450