What are the steps to convert
1 - 0110 0101 - 110 0111 1000 0000 0001 0000, 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:
0110 0101
The last 23 bits contain the mantissa:
110 0111 1000 0000 0001 0000
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
0110 0101(2) =
0 × 27 + 1 × 26 + 1 × 25 + 0 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 1 × 20 =
0 + 64 + 32 + 0 + 0 + 4 + 0 + 1 =
64 + 32 + 4 + 1 =
101(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 = 101 - 127 = -26
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 0111 1000 0000 0001 0000(2) =
1 × 2-1 + 1 × 2-2 + 0 × 2-3 + 0 × 2-4 + 1 × 2-5 + 1 × 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 + 1 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 0 × 2-23 =
0.5 + 0.25 + 0 + 0 + 0.031 25 + 0.015 625 + 0.007 812 5 + 0.003 906 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 001 907 348 632 812 5 + 0 + 0 + 0 + 0 =
0.5 + 0.25 + 0.031 25 + 0.015 625 + 0.007 812 5 + 0.003 906 25 + 0.000 001 907 348 632 812 5 =
0.808 595 657 348 632 812 5(10)
= -0.000 000 026 950 175 424 644 839 949 905 872 344 97
1 - 0110 0101 - 110 0111 1000 0000 0001 0000, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = -0.000 000 026 950 175 424 644 839 949 905 872 344 97(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.