What are the steps to convert
1 - 0111 1000 - 001 0101 0001 1000 0010 0001, 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:
0111 1000
The last 23 bits contain the mantissa:
001 0101 0001 1000 0010 0001
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
0111 1000(2) =
0 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
0 + 64 + 32 + 16 + 8 + 0 + 0 + 0 =
64 + 32 + 16 + 8 =
120(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 = 120 - 127 = -7
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).
001 0101 0001 1000 0010 0001(2) =
0 × 2-1 + 0 × 2-2 + 1 × 2-3 + 0 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 0 × 2-8 + 0 × 2-9 + 0 × 2-10 + 1 × 2-11 + 1 × 2-12 + 0 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 1 × 2-18 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 1 × 2-23 =
0 + 0 + 0.125 + 0 + 0.031 25 + 0 + 0.007 812 5 + 0 + 0 + 0 + 0.000 488 281 25 + 0.000 244 140 625 + 0 + 0 + 0 + 0 + 0 + 0.000 003 814 697 265 625 + 0 + 0 + 0 + 0 + 0.000 000 119 209 289 550 781 25 =
0.125 + 0.031 25 + 0.007 812 5 + 0.000 488 281 25 + 0.000 244 140 625 + 0.000 003 814 697 265 625 + 0.000 000 119 209 289 550 781 25 =
0.164 798 855 781 555 175 781 25(10)
= -0.009 099 991 060 793 399 810 791 015 625
1 - 0111 1000 - 001 0101 0001 1000 0010 0001, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = -0.009 099 991 060 793 399 810 791 015 625(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.