用递等式计算。（能简便计算的用简便方法计算） 2.5×（3.8×0.4）

2.5×（3.8×0.4） 4.6×0.33+5.4×0.33
= 3.8*（2.5*0.4） =0.33*（4.6+5.4）
=3.8*1 =0.33*10
=3.8 =3.3

0.25×39+0.25 8.36－2.48－3.52
= 0.25*（39+1） =8.36-（2.48+3.52）
= 0.25*40 =8.36-6
=10 =2.36

2.5×（3.8×0.4）
= 2.5x0.4x3.8
=1x3.8
= 3.8

4.6×0.33+5.4×0.33
=(4.6+5.4)x0.33
=10x0.33
=3.3;

0.25×39+0.25
=0.25x(39+1)
=0.25x40
=10;

8.36－2.48－3.52
=8.36-(2.48+3.52)
=8.36-6
=2.36.

供参考。