7846 = 7000 + 800 + 40 + 6 = 7 × 103 + 8 × 102 + 4 × 101 + 6 × 100
405912 = 400000 + 0 + 5000 + 900 + 10 + 2 = 4 × 105 + 0 × 104 + 5 × 103 + 9 × 102 + 1 × 101 + 2 × 100