What are the steps to convert
1 - 1101 0100 - 000 0000 0100 0111 1010 1000, 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:
1101 0100
The last 23 bits contain the mantissa:
000 0000 0100 0111 1010 1000
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
1101 0100(2) =
1 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 0 × 20 =
128 + 64 + 0 + 16 + 0 + 4 + 0 + 0 =
128 + 64 + 16 + 4 =
212(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 = 212 - 127 = 85
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).
000 0000 0100 0111 1010 1000(2) =
0 × 2-1 + 0 × 2-2 + 0 × 2-3 + 0 × 2-4 + 0 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 1 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 1 × 2-13 + 1 × 2-14 + 1 × 2-15 + 1 × 2-16 + 0 × 2-17 + 1 × 2-18 + 0 × 2-19 + 1 × 2-20 + 0 × 2-21 + 0 × 2-22 + 0 × 2-23 =
0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.001 953 125 + 0 + 0 + 0 + 0.000 122 070 312 5 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0.000 015 258 789 062 5 + 0 + 0.000 003 814 697 265 625 + 0 + 0.000 000 953 674 316 406 25 + 0 + 0 + 0 =
0.001 953 125 + 0.000 122 070 312 5 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0.000 015 258 789 062 5 + 0.000 003 814 697 265 625 + 0.000 000 953 674 316 406 25 =
0.002 186 775 207 519 531 25(10)
= -38 770 222 995 990 165 594 308 608
1 - 1101 0100 - 000 0000 0100 0111 1010 1000, a 32 bit single precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (float) = -38 770 222 995 990 165 594 308 608(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.