几道小学简便运算题、0.8 X 0.25 + 0.80.49 X 10.11.25 X 7.5 X 0.8 - 5.65.9 X 10 - 5.9 X 30.57 X 101 - 0.57就是这些了,希望大家帮帮忙……本人上5年纪.有些题不是太会哈……

0.8 X (1+0.25)=0.8x1.25=1 0.49x(10+0.1)=4.9+0.049=4.049
(1.25x0.8)X7.5-5.6=7.5-5.6=1.9 5.9x(10-3)=5.9x7=41.3
0.57x(101-1)=0.57x100=57

0.8 X 0.25 + 0.8
=(1+0.25)X0.8
=1.25X0.8
=1
0.49 X 10.1
=0.49x(10+0.1)
=0.49x10+0.1x.49
=4.9+0.049
=4.949
1.25 X 7.5 X 0.8 - 5.6
=1.25x0.8x7.5-5.6
=1x7.5-5.6
=1.9
5.9 X 10 - 5.9 X 3
=5.9x(10-3)
=5.9x7
=41.3
0.57 X 101 - 0.57
=0.57x(101-1)
=0.57x100
=57

0.8 X 0.25 + 0.8
=0.8*(0.25+1)
=0.8*1.25
=1
0.49 X 10.1
=0.49*(10+0.1)
=0.49*10+0.49*0.1
=4.9+0.049
=4.949
1.25 X 7.5 X 0.8 - 5.6
=(1.25*0.8)*7.5-5.6
=7.5-5.6
=1.9
5.9 X 10 - 5.9 X 3
=5.9*(10-3)
=5.9*7
=(6-0.1)*7
=42-0.7
=41.3
0.57 X 101 - 0.57
=0.57*(101-1)
=0.57*100
=57

0.57*(101-100)