一、口算:
12+6= 29-7= 33+2= 3+40= 15+4= 53+6= 78+5=
23+5= 37+1= 29-3= 38-3= 15-4= 36+8= 19+6=
18-2= 30+8= 43+1= 86+2= 70+3= 47+6= 39+8=
30-2= 72-2= 66-4= 39-2= 20-9= 83+70= 67+40=
53+5= 35+2= 39-4= 8+50= 20-1= 17+9= 40+6=
62+7= 89-5= 63+3= 34-2= 28+50= 50-4= 11+2=
53-3= 60+8= 80-7= 68+5= 32+4= 26-5= 84+4=
35-10= 71+9= 88+3= 18-4= 66+10= 83-3= 95-40=
71+5= 60-5= 36+3= 58+30= 28-7= 87-10= 62-2=
80-6= 11+9= 80-3= 95-4= 64+3= 98-4= 25+7=
83+5= 83+10= 10+8= 56+20= 64+6= 65+3= 15-3=
30-3= 32+6= 29-7= 35+2= 73+4= 25+4= 43+5=
87+10= 39-3= 48-30= 81-2= 60+8= 39+10= 76+10=
70+30= 48-9= 47-8= 52-4= 43-8= 68-9= 40-2=
27-9= 32-4= 41-2= 38-9= 50-8= 63-9= 37-8=
56-20= 88-9= 75-9= 92-3= 42-7= 71-6= 58-10=
47-8= 26-7= 52-3= 69-10= 63-5= 80-2= 36-9=
78-4= 65-8= 99-9= 72-2= 45-9= 86-8= 96-2=
24-9= 40-2= 46-9= 43-4= 18-2= 38-8= 38-9=
35+5= 85+2= 59-4= 78+10= 82-5= 66-4= 39-2=
20-9= 64+6= 32+7= 49-5= 63+3= 84-2= 72-2=
60-4= 11+20= 45-3= 30+8= 60-7= 39-4= 8+50=
25+4= 36-5= 84+4= 52-3= 71+9= 35+2= 20-1=
88-4= 76+0= 93-3= 18+5= 70-5= 62+7= 89-5=