二年级口算题:两位数减两位数的减法 (1)55 + 34 = (2)54 + 53 = (3)58 + 51 = (4)38 + 20 = (5)60 + 58 = (6)84 + 33 = (7)71 + 41 = (8)24 + 17 = (9)33 + 23 = (10)91 + 35 = (11)31 + 25 = (12)70 + 21 = (13)82 + 16 = (14)38 + 23 = (15)91 + 11 =