What are the steps to convert
1 - 0101 0111 - 100 1101 0100 0011 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:
0101 0111
The last 23 bits contain the mantissa:
100 1101 0100 0011 0001 0000
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
0101 0111(2) =
0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 1 × 21 + 1 × 20 =
0 + 64 + 0 + 16 + 0 + 4 + 2 + 1 =
64 + 16 + 4 + 2 + 1 =
87(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 = 87 - 127 = -40
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).
100 1101 0100 0011 0001 0000(2) =
1 × 2-1 + 0 × 2-2 + 0 × 2-3 + 1 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 0 × 2-8 + 1 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 0 × 2-13 + 1 × 2-14 + 1 × 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 + 0 + 0.062 5 + 0.031 25 + 0 + 0.007 812 5 + 0 + 0.001 953 125 + 0 + 0 + 0 + 0 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0 + 0 + 0 + 0.000 001 907 348 632 812 5 + 0 + 0 + 0 + 0 =
0.5 + 0.062 5 + 0.031 25 + 0.007 812 5 + 0.001 953 125 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0.000 001 907 348 632 812 5 =
0.603 609 085 083 007 812 5(10)
= -0.000 000 000 001 458 473 966 597 928 495 048 108 73
1 - 0101 0111 - 100 1101 0100 0011 0001 0000, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = -0.000 000 000 001 458 473 966 597 928 495 048 108 73(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.