What are the steps to convert
0 - 0101 1111 - 100 1000 0000 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:
0101 1111
The last 23 bits contain the mantissa:
100 1000 0000 0000 0000 0010
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
0101 1111(2) =
0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 1 × 20 =
0 + 64 + 0 + 16 + 8 + 4 + 2 + 1 =
64 + 16 + 8 + 4 + 2 + 1 =
95(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 = 95 - 127 = -32
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 1000 0000 0000 0000 0010(2) =
1 × 2-1 + 0 × 2-2 + 0 × 2-3 + 1 × 2-4 + 0 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 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 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 1 × 2-22 + 0 × 2-23 =
0.5 + 0 + 0 + 0.062 5 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 238 418 579 101 562 5 + 0 =
0.5 + 0.062 5 + 0.000 000 238 418 579 101 562 5 =
0.562 500 238 418 579 101 562 5(10)
= 0.000 000 000 363 797 936 220 322 526 423 842 646 18
0 - 0101 1111 - 100 1000 0000 0000 0000 0010, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = 0.000 000 000 363 797 936 220 322 526 423 842 646 18(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.