143×12=1716;
1 4 3
×
1 2
2 8 6
1 4 3 1 7 1 6
405×36=14580;
4 0 5
×
3 6
2 4 3 0
1 2 1 5 1 4 5 8 0
160×40=6400;
1 6 0
×
4 0
6 4 0 0
69÷23=3;
3
23
6 9
6 9 0
200÷25=8;
8
25
2 0 0
2 0 0 0
342÷26=13…4.
1 3
26
3 4 2
2 6 8 2
7 8 4