练习题
1.口算练习
10-7= 10-3= 9+1= 5-1= 7+1= 7-5= 8-2= 10-6=
2+8= 5+3= 3+6= 7-4= 7-1= 6+2= 9+1= 5-3= 10-1= 9-2= 1+2= 6+2= 5+5= 6+1= 1+9= 7-2= 10-1= 5-3= 3+1= 3+7= 9-6= 2+4=
5+1= 2+2= 7-4= 1+4= 5+2= 9-5=6+3= 5-2= 4-3=1+1= 9-3= 8-1= 8+2= 4+2=5-2= 1+4= 6-4= 2+8=
8-1= 9-4= 7+1= 7-5= 10-3= 7+2= 9-8=
2+1= 6+3= 1+8= 2+4= 10-9= 8-3= 3+1=
1+4= 6-1= 9+1= 2+6= 4+1= 3+4=