Convert the following into Hindu-Arabic numerals.

1. \(3 \times 10^{2}+4 \times 10^{1}+8 \times 10^{0}\)

2. \(5 \times 10^{3}+0 \times 10^{2}+9 \times 10^{1}+9 \times 10^{0}\)

3. \(6 \times 10^{6}+2 \times 10^{5}+0 \times 10^{4}+9 \times 10^{3}+1 \times 10^{2}+1 \times 10^{1}+7 \times 10^{0}\)