What are the steps to convert
1 - 1000 0011 - 010 0000 1000 0110 0001 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.
1
The next 8 bits contain the exponent:
1000 0011
The last 23 bits contain the mantissa:
010 0000 1000 0110 0001 0100
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
1000 0011(2) =
1 × 27 + 0 × 26 + 0 × 25 + 0 × 24 + 0 × 23 + 0 × 22 + 1 × 21 + 1 × 20 =
128 + 0 + 0 + 0 + 0 + 0 + 2 + 1 =
128 + 2 + 1 =
131(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 = 131 - 127 = 4
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).
010 0000 1000 0110 0001 0100(2) =
0 × 2-1 + 1 × 2-2 + 0 × 2-3 + 0 × 2-4 + 0 × 2-5 + 0 × 2-6 + 0 × 2-7 + 1 × 2-8 + 0 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 1 × 2-13 + 1 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 0 × 2-18 + 1 × 2-19 + 0 × 2-20 + 1 × 2-21 + 0 × 2-22 + 0 × 2-23 =
0 + 0.25 + 0 + 0 + 0 + 0 + 0 + 0.003 906 25 + 0 + 0 + 0 + 0 + 0.000 122 070 312 5 + 0.000 061 035 156 25 + 0 + 0 + 0 + 0 + 0.000 001 907 348 632 812 5 + 0 + 0.000 000 476 837 158 203 125 + 0 + 0 =
0.25 + 0.003 906 25 + 0.000 122 070 312 5 + 0.000 061 035 156 25 + 0.000 001 907 348 632 812 5 + 0.000 000 476 837 158 203 125 =
0.254 091 739 654 541 015 625(10)
= -20.065 467 834 472 656 25
1 - 1000 0011 - 010 0000 1000 0110 0001 0100, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = -20.065 467 834 472 656 25(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.