a) 84 = 8 × 10 + 4 × 1
б) 207 = 2 × 100 + 0 × 10 + 7 × 1
в) 38 407 = 3 × 10 000 + 8 × 1 000 + 4 × 100 + 0 × 10 + 7 × 1
г) 882 735 = 8 × 100 000 + 8 × 10 000 + 2 × 1 000 + 7 × 100 + 3 × 10 + 5 × 1
д) 5 021 020 = 5 × 1 000 000 + 0 × 100 000 + 2 × 10 000 + 1 × 1 000 + 0 × 100 + 2 × 10 + 0 × 1