(1)0.58×0.24=0.1392;
0.5 8
×0.2 4 2 3 2
1 1 6 0. 1 3 9 2
验算:
0.2 4
×0.5 8 1 9 2
1 2 0 0.1 3 9 2
(2)1.57÷3.9≈0.40;
0.4 0 2
3.9
1.5 7
1 5 6 1 0 0
7 8 2 2
(3)3.42×0.25=0.855;
3.4 2
×0.2 5 1 7 1 0
6 8 4 0.8 5 5 0
(4)70.7÷33=2.
4? 1
.? 2
2.142142…
33
70.7
66 4 7
3 3 1 4 0
1 3 2 8 0
6 6 1 4 0
1 3 2 8 0
6 6 1 4