四年级口算1000题(20)

33 + 57 + 48 = 34 + 66 + 64 = 35 + 75 + 80 = 36 + 84 + 96 = 37 + 93 + 112 = 38 + 102 + 128 = 39 + 111 + 144 = 40 -30 -140 = 41 -21 -124 = 42 -12 -108 = 43 -3 -92 = 44 + 6 -76 = 45 + 15 -60 = 46 + 24 -44 = 47 + 33 -28 = 48 + 42 -12 = 49 + 51 + 4 = 50 + 60 + 20 = 51 + 69 + 36 = 52 + 78 + 52 = 53 + 87 + 68 = 54 + 96 + 84 =