What are the steps to convert
0 - 1111 1110 - 110 1101 1011 1100 0010 0110, a 32 bit single precision IEEE 754 binary floating point representation standard to decimal?
1. Identify the elements that make up the binary representation of the number:
The first bit (the leftmost) indicates the sign,
1 = negative, 0 = positive.
0
The next 8 bits contain the exponent:
1111 1110
The last 23 bits contain the mantissa:
110 1101 1011 1100 0010 0110
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
1111 1110(2) =
1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 0 × 20 =
128 + 64 + 32 + 16 + 8 + 4 + 2 + 0 =
128 + 64 + 32 + 16 + 8 + 4 + 2 =
254(10)
3. Adjust the exponent.
Subtract the excess bits: 2(8 - 1) - 1 = 127,
that is due to the 8 bit excess/bias notation.
The exponent, adjusted = 254 - 127 = 127
4. Convert the mantissa from binary (from base 2) to decimal (in base 10).
The mantissa represents the fractional part of the number (what comes after the whole part of the number, separated from it by a comma).
110 1101 1011 1100 0010 0110(2) =
1 × 2-1 + 1 × 2-2 + 0 × 2-3 + 1 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 1 × 2-8 + 0 × 2-9 + 1 × 2-10 + 1 × 2-11 + 1 × 2-12 + 1 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 1 × 2-18 + 0 × 2-19 + 0 × 2-20 + 1 × 2-21 + 1 × 2-22 + 0 × 2-23 =
0.5 + 0.25 + 0 + 0.062 5 + 0.031 25 + 0 + 0.007 812 5 + 0.003 906 25 + 0 + 0.000 976 562 5 + 0.000 488 281 25 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0 + 0 + 0 + 0 + 0.000 003 814 697 265 625 + 0 + 0 + 0.000 000 476 837 158 203 125 + 0.000 000 238 418 579 101 562 5 + 0 =
0.5 + 0.25 + 0.062 5 + 0.031 25 + 0.007 812 5 + 0.003 906 25 + 0.000 976 562 5 + 0.000 488 281 25 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0.000 003 814 697 265 625 + 0.000 000 476 837 158 203 125 + 0.000 000 238 418 579 101 562 5 =
0.857 304 334 640 502 929 687 5(10)
= 316 003 957 541 994 548 235 842 116 591 883 911 168
0 - 1111 1110 - 110 1101 1011 1100 0010 0110, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = 316 003 957 541 994 548 235 842 116 591 883 911 168(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.