文档介绍：2+18= 18-6= 16-1=
2+12= 5+11= 17-7=
5+1= 10-1= 12+5=
11-2= 15+1= 19-11=
10+9= 16-7= 2+15=
16-15= 15+3= 9-4=
20-1= 11-10= 6+8=
2+5= 2+6= 10+1=
17-16= 13+4= 20-1=
1+2= 20-3= 2+7=
19-6= 15-12= 9+1=
14-1= 5+2= 13+7=
19-4= 3+5= 17+3=
3+8= 8+4= 17+3=
17+3= 4+12= 14+3=
1+14= 1+5= 3+14=
13-3= 10+2= 9-8 =
12-8= 2+5= 19-18=
14+3= 17-3= 9-4=
6+13= 13+5= 3+7=
12+3= 5+6= 17-1=
5+2= 7+7= 6+7=
12-11= 20-13= 13+6=
15-5= 20-1= 5+8=
18-12= 7+1= 20-6=
8+6= 3+13= 1+19=
17-16= 7+13= 10-2=
11+6= 1+8= 14+2=
9+5= 2+10= 1+12=
8+12= 11-10= 3+3=
3+17= 8+4= 8+2=
2-1= 1+4= 9+9=
8+7= 20-18= 19-5=
5+6= 20-3= 17-10=
1+16= 9+1= 9+10=
10-2= 18-17= 6+14=
18-8= 9+6= 8-6=
7-5= 13+2= 19-12=
11+9= 17-12= 16-4=
13-1= 16-8= 2+12=
2+8= 15-8= 19-16=
19-4= 14+3= 3+4=
19-17= 5-1= 15+5=
20-1= 19-10= 7-1=
6-3= 6+13= 11-3=
11+7= 10+4= 20-15=
17-7= 7-6= 19-16=
14+3= 5+8= 20-19=
5+13= 1+8= 9+7=
13-2= 9-1= 17-9=
6-1= 18-4= 14-13=
10-1= 15-2= 12-2=
3+5= 9+5= 13-1=
18-13= 12+8= 11+7=
6+7= 15-5= 16-5=
12-1= 4+5= 13+4=
5-2= 7-2= 5+3=
4+12= 15+5= 12+1=
3+7= 14-6= 7+8=
3+6= 16-6= 19-16=
20-9= 11-9= 13-7=
4+11= 1+18= 19-18=
7+13= 1+7= 13+2=
17-8= 17-7= 2+5=
3-2= 7+10= 16-10=
5+6= 11-10= 18-16=
14-2= 18-2= 11+7=
7+12= 9-1= 10-8=
20-15= 10-9= 20-8=
20-11= 20-5= 20-18=
14+2= 14-10= 6+11=
12+7= 12-10= 14+5=
18-4= 9+8= 6+3=
16-4= 18-12= 1+17=
14+2= 4+4= 10-2=
14-6= 12-6= 12+6=
11-3= 15+2= 5+13=
9+6= 2+1= 16-14=
1+8= 4+12= 3+13=
14-3= 18-5= 7+6=
12+1= 12-1= 19-15=
18-1= 13-11= 16+1=
9-2= 16-7= 16-15=
18-14= 18-5= 16+4=
20-16= 17-5= 20-19=
10-5= 11-4= 1+8=
16-11= 17-5= 6+2=
6+10= 14-9= 18-11=
2+13= 6+8= 13-12=
13-3= 8+5= 19-4=
19-18= 7-4= 6+13=
17-3= 1+17= 20-6=
7-2= 5-2= 7+3=
14-2= 15+4= 14-8=
17-6= 11-2= 20-15=
6+2= 11-8= 9-4=
16-6= 14+1= 2+5=
2+17= 2+10= 8+12=
14+3= 8-2= 17