一年级下学期口算练习5+63= 60-60= 41+20= 69-8=90-9= 67-6= 63+7= 100-4=97-70= 97-2= 31+8= 77-6=6+27= 3+87= 84-8= 100-40=96+3= 38+20= 40+28= 55+2=49+3= 5+49= 85-80= 5+48=88-4= 74+20= 3+36= 20+49=73-5= 71...