What are the steps to convert
0 - 0000 0100 - 011 1101 1000 0000 0000 0100, 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:
0000 0100
The last 23 bits contain the mantissa:
011 1101 1000 0000 0000 0100
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
0000 0100(2) =
0 × 27 + 0 × 26 + 0 × 25 + 0 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 0 × 20 =
0 + 0 + 0 + 0 + 0 + 4 + 0 + 0 =
4 =
4(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 = 4 - 127 = -123
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).
011 1101 1000 0000 0000 0100(2) =
0 × 2-1 + 1 × 2-2 + 1 × 2-3 + 1 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 1 × 2-8 + 0 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 0 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 0 × 2-18 + 0 × 2-19 + 0 × 2-20 + 1 × 2-21 + 0 × 2-22 + 0 × 2-23 =
0 + 0.25 + 0.125 + 0.062 5 + 0.031 25 + 0 + 0.007 812 5 + 0.003 906 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 476 837 158 203 125 + 0 + 0 =
0.25 + 0.125 + 0.062 5 + 0.031 25 + 0.007 812 5 + 0.003 906 25 + 0.000 000 476 837 158 203 125 =
0.480 469 226 837 158 203 125(10)
= 0.000 000 000 000 000 000 000 000 000 000 000 000 13
0 - 0000 0100 - 011 1101 1000 0000 0000 0100, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = 0.000 000 000 000 000 000 000 000 000 000 000 000 13(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.