一、用直尺画竖式的 横线25+37= 91-49= 80-54= 48+36=66-47= 21+69= 75-20= 71+10= 75-50= 37-10= 50-40= 76-50=36+27+28= 93-35-19= 21-20+15=96-90+20= 37-10-20= 62+30-22=74-20+17= 92-20-48= 21+69+30=76-50= 12+10= 83-10= 81-30=16-10= 73-70= 63+10= 15+10=31-30= 96-20= 69-30= 98-40=48+25+8= 26+22+14= 61-28+25= 38+13+34= 50-34+18= 35-26-25= 54-25-56= 20+22-25= 62-22-14=72+10= 92-70= 44-30= 78-30=77-10= 79-20= 88-30= 62-30=79-10= 32+30= 80-70= 43+40=55-20-24= 65-25+26 = 75-55+56=22+22+14 = 77-46-72= 65-25-26 = 75-25-36= 12+26+27= 54-27-26=32-30= 93-70= 65-40= 36+10=97-70= 29+20= 63-40= 17+40= 99-10= 76-70= 88-50= 32+6=4+27-26= 57-27-21= 27-16+72 = 62-15+14= 75-25-35= 26+16+23=67-22-26= 70-27-25= 77-27-4 = 23+6= 64+5= 87+0= 67-7= 97+1= 59+1= 79-5= 77-2=63+5= 71+8= 57+6= 94+8= 40+12+23= 54+46-12 = 65-35+25= 95-50-