What are the steps to convert
1 - 1111 1101 - 011 0000 0110 1101 1100 1001, 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:
1111 1101
The last 23 bits contain the mantissa:
011 0000 0110 1101 1100 1001
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
1111 1101(2) =
1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 0 × 21 + 1 × 20 =
128 + 64 + 32 + 16 + 8 + 4 + 0 + 1 =
128 + 64 + 32 + 16 + 8 + 4 + 1 =
253(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 = 253 - 127 = 126
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).
011 0000 0110 1101 1100 1001(2) =
0 × 2-1 + 1 × 2-2 + 1 × 2-3 + 0 × 2-4 + 0 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 1 × 2-9 + 1 × 2-10 + 0 × 2-11 + 1 × 2-12 + 1 × 2-13 + 0 × 2-14 + 1 × 2-15 + 1 × 2-16 + 1 × 2-17 + 0 × 2-18 + 0 × 2-19 + 1 × 2-20 + 0 × 2-21 + 0 × 2-22 + 1 × 2-23 =
0 + 0.25 + 0.125 + 0 + 0 + 0 + 0 + 0 + 0.001 953 125 + 0.000 976 562 5 + 0 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0 + 0.000 030 517 578 125 + 0.000 015 258 789 062 5 + 0.000 007 629 394 531 25 + 0 + 0 + 0.000 000 953 674 316 406 25 + 0 + 0 + 0.000 000 119 209 289 550 781 25 =
0.25 + 0.125 + 0.001 953 125 + 0.000 976 562 5 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0.000 030 517 578 125 + 0.000 015 258 789 062 5 + 0.000 007 629 394 531 25 + 0.000 000 953 674 316 406 25 + 0.000 000 119 209 289 550 781 25 =
0.378 350 377 082 824 707 031 25(10)
= -117 257 082 190 027 911 914 167 540 053 367 062 528
1 - 1111 1101 - 011 0000 0110 1101 1100 1001, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = -117 257 082 190 027 911 914 167 540 053 367 062 528(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.