What are the steps to convert
0 - 1000 0101 - 100 0111 1010 0000 0000 0010, 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:
1000 0101
The last 23 bits contain the mantissa:
100 0111 1010 0000 0000 0010
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
1000 0101(2) =
1 × 27 + 0 × 26 + 0 × 25 + 0 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 1 × 20 =
128 + 0 + 0 + 0 + 0 + 4 + 0 + 1 =
128 + 4 + 1 =
133(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 = 133 - 127 = 6
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 0111 1010 0000 0000 0010(2) =
1 × 2-1 + 0 × 2-2 + 0 × 2-3 + 0 × 2-4 + 1 × 2-5 + 1 × 2-6 + 1 × 2-7 + 1 × 2-8 + 0 × 2-9 + 1 × 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 + 0 × 2-21 + 1 × 2-22 + 0 × 2-23 =
0.5 + 0 + 0 + 0 + 0.031 25 + 0.015 625 + 0.007 812 5 + 0.003 906 25 + 0 + 0.000 976 562 5 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 238 418 579 101 562 5 + 0 =
0.5 + 0.031 25 + 0.015 625 + 0.007 812 5 + 0.003 906 25 + 0.000 976 562 5 + 0.000 000 238 418 579 101 562 5 =
0.559 570 550 918 579 101 562 5(10)
= 99.812 515 258 789 062 5
0 - 1000 0101 - 100 0111 1010 0000 0000 0010, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = 99.812 515 258 789 062 5(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.