.

14-2-6= 12-10-2= 18-4-7= 17-10-6= 16-9-3= 4+10+6= 13-8-4= 2+10+2= 15+2+2= 3+7+8= 8+5+5= 10+5+2= 15-6-8= 10-6-3= 14-3-10= 2+8+9= 18-5-8= 14-7-4= 17-4-5= 5+6+7= 16-2-9= 17-7-6= 20-1-4= 9+2+6= .

3+4+2= 10+4+1= 1+8+6= 15-5-7= 20-3-8= 5+9+2= 18-7-7= 11-2-2= 17-1-9= 2+6+3= 15-4-2= 8+4+8= 3+9+3= 7+7+3= 20-9-8= 6+7+3= 9+9+2= 6+9+4= 18-9-6= 19-1-8= 14-6-5= 11-1-5= 19-8-1= 19-5-7= 19-7-5= 16-7-1= 9+3+4= 2+6+10= 4+4+3= 15-10-5= 6+5+1= 15-1-9= 10+8+2= 20-4-8= 19-4-5= 11-5-2=

.

18-10-5= 13-4-1= 15-2-10= 4+6+2= 15-3-8= 19-5-6= 17-3-8= 3+7+10= 2+7+4= 10-8-1= 20-5-2= 10+3+1= 6+2+7= 8+6+7= 6+6+1= 4+6+9= 3+10+4= 16-4-7= 9+2+8= 8+1+6= 13-5-6= 20-1-7= 18-4-6= 17-6-4= .

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

.

17-7-9= 13-4-3= 5+3+1= 9+4+3= 9+7+4= 8+8+3= 18-5-7= 4+4+10= 1+9+10= 4+5+7= 16-8-6= 1+4+10= 1+12+4= 6+4+6= 13-2-4= 5+6+9= 4+8+4= 18-3-9= 2+3+8= 15-5-6= 14-5-9= 19-10-4= 6+7+5= 3+8+7= .

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

.

一、在（）里填上合适的数。

( )+5=12 11+( )=19 20-( )=15 10+( )=20 ( )-2=18 13+( )=16 ( )-5=9 9+( )=15 17-( )=7 ( )+6=11 17-( )=17 18-( )=9 17-( )=10 ( )-12=3 4+( )=8 .

16-( )=0 ( )+7=17 9+( )=17 19-( )=7 ( )-4=10 ( )+2=11 ( )+7=15 6+( )=12 3+( )=11 ( )+8=14 ( )-5=10 13-( )=10 10+( )=16 7+( )=15 ( )+12=12 13+( )=16 5+( )=14 11-( )=5 14+( )=18 ( )+8=12 ( )-8=8 ( )+5=18 2+( 5+( )=10 9+( )=18

)=10