简便计算。4.4×0.25，0.26×5.5+2.6×0.45，19.9×0.67，0.8×32.

Question

简便计算。4.4×0.25，0.26×5.5+2.6×0.45，19.9×0.67，0.8×32.4×12.5

Answer 1

4.4*0.25的简便计算
=(4+0.4)*0.25
=4*0.25+0.4*0.25
=1+0.1
=1.1
0.26×5.5+2.6×0.45
＝2.6×0.55＋2.6×0.45
＝2.6×（0.55＋0.45）
＝2.6×1
2.6
19.9×0.67
=0.67x(20-0.1)
=0.67x20-0.67x0.1
=13.4-0.067
=13.333
=0.8*12.5*32.4
=10*32.4
=324