The decimal number that corresponds to the binary number 11111111 is 255. This is because the binary number 11111111 has eight bits, each representing a power of 2 starting from 202^020 at the rightmost bit to 272^727 at the leftmost bit. When converting, you calculate:
1×27+1×26+1×25+1×24+1×23+1×22+1×21+1×20=128+64+32+16+8+4+2+1=2551\times 2^7+1\times 2^6+1\times 2^5+1\times 2^4+1\times 2^3+1\times 2^2+1\times 2^1+1\times 2^0 =128+64+32+16+8+4+2+1=2551×27+1×26+1×25+1×24+1×23+1×22+1×21+1×20=128+64+32+16+8+4+2+1=255
Therefore, binary 11111111 equals decimal 255.
