. 1 = 0 3 – 3 = 0 4 4 0 4 0 = – 4 5 0 =– 5 5 0 5 5 0 = – 5 4 0 = – 4 2: TÝnh 4 + 1 = 4 + 0 = 4 0 =– 2 + 0 = 2 – 2 = 2 0 =– 3. ViÕt phÐp tÝnh cho thÝch hîp : a) 3 - 3 = 0 3 thÝch hîp : a) 3 - 3 = 0 3. ViÕt phÐp tÝnh cho thÝch hîp : b) 2 - 2 = 0 1 - 1 = 0 1 - 0 = 1 2 - 2 = 0 2 - 0 = 2