56+37-80+16=29 31.5+5=36.5 12-1.1=10.9 1.2×0.2=0.24
2.87÷0.7=4.1 1÷
4
5 =1
1
4
1
6 +
5
6 =1
7
15 -
1
15 =
2
5
4
15 ÷
2
5 =
2
3
3
8 ×
4
5 =0.3 30÷50=0.6 0×
7
8 =0
25×8=200
1
4 +
1
5 =
9
20 12×
2
3 =8 故答案为:-3,36.5,10.9,0.24,4.1,1
1
4 ,1,
2
5 ,
2
3 ,0.3,0.6,0,200,
9
20 ,8.