能用简便方法的就用简便方法计算

0.99×3.5
=（1-0.01）×3.5
=1×3.5-0.01×3.5
=3.5-0.35
=3.15

(0.75+0.9)×4
=0.75×4+0.9×4
=3+3.6
=6.6

2.5×40.1
=2.5×（40+0.1）
=2.5×40+25×0.1
=100+2.5
=102.5

1.25×2.5×32
=1.25×2.5×4×8
=（1.25×8）×（2.5×4）
=10×10
=100

0.79×4.8+0.79×5.2
=0.79×（4.8+5.2）
=0.79×10
=7.9

6.23-5.46×4
=6.23-2.184
=4.046

真抠一分没有 不告诉你了

0.99乘3.5=1*3.5-0.01*3.5=3.5-0.035=3.465
（0.75+0.9）乘0.4=0.75*0.4+0.9*0.4=0.3+0.36=0.66
2.5乘40.1=40*2.5+2.5*0.1=100+0.25=100.25
1.25乘0.25乘32=5/4*1/4*32=10
0.79乘4.8+0.79乘5.2 =0.79*(4.8+5.2)=0.79*10=7.9