You are converting from base 2 to base 10 numeral.
[tex](011001111)_2 =0 \times {2}^{8} + 1 \times {2}^{7} + 1\times {2}^{6} + 0\times {2}^{5} + 0 \times {2}^{4} + 1 \times {2}^{3} + 1 \times {2}^{2} + 1 \times {2}^{1} + 1 \times {2}^{0} [/tex]
[tex](011001111)_2 =0 \times 256 + 1 \times 128 + 1\times 64 + 0\times 32 + 0 \times 16 + 1 \times 8 + 1 \times 4 + 1 \times 2 + 1 \times 1[/tex]
[tex](011001111)_2 =0 + 128 +64 + 0+ 0 + 8 + 4 + 2 + 1[/tex]
[tex](011001111)_2 =207[/tex]
