= 3 − 8 = (3 × 10) − 8 = 30 − 8 = 22 8.000 + 4.000 = 12.000 − 4 = 3 × ( − 4) + 2 = 2 × ( + 2) − 4 = 3 − 12 + 2 = 2 + 4