32 Bit IEEE 754 Binary to Float: Convert 1 - 0101 1001 - 011 0101 0011 0000 0011 1000, Number Written in 32 Bit Single Precision IEEE 754 Binary Floating Point Standard Representation, to a Base Ten Decimal System Float
1 - 0101 1001 - 011 0101 0011 0000 0011 1000: 32 bit single precision IEEE 754 binary floating point standard representation number converted to a base ten decimal system float
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 1001
The last 23 bits contain the mantissa:
011 0101 0011 0000 0011 1000
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
0101 1001(2) =
0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 1 × 20 =
0 + 64 + 0 + 16 + 8 + 0 + 0 + 1 =
64 + 16 + 8 + 1 =
89(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 = 89 - 127 = -38
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 0101 0011 0000 0011 1000(2) =
0 × 2-1 + 1 × 2-2 + 1 × 2-3 + 0 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 0 × 2-8 + 0 × 2-9 + 1 × 2-10 + 1 × 2-11 + 0 × 2-12 + 0 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 1 × 2-18 + 1 × 2-19 + 1 × 2-20 + 0 × 2-21 + 0 × 2-22 + 0 × 2-23 =
0 + 0.25 + 0.125 + 0 + 0.031 25 + 0 + 0.007 812 5 + 0 + 0 + 0.000 976 562 5 + 0.000 488 281 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 003 814 697 265 625 + 0.000 001 907 348 632 812 5 + 0.000 000 953 674 316 406 25 + 0 + 0 + 0 =
0.25 + 0.125 + 0.031 25 + 0.007 812 5 + 0.000 976 562 5 + 0.000 488 281 25 + 0.000 003 814 697 265 625 + 0.000 001 907 348 632 812 5 + 0.000 000 953 674 316 406 25 =
0.415 534 019 470 214 843 75(10)
5. Put all the numbers into expression to calculate the single precision floating point decimal value:
(-1)Sign × (1 + Mantissa) × 2(Adjusted exponent) =
(-1)1 × (1 + 0.415 534 019 470 214 843 75) × 2-38 =
-1.415 534 019 470 214 843 75 × 2-38 =
-0.000 000 000 005 149 682 763 549 989 772 400 294 89
1 - 0101 1001 - 011 0101 0011 0000 0011 1000 converted from a 32 bit single precision IEEE 754 binary floating point standard representation number to a decimal system number, written in base ten (float) = -0.000 000 000 005 149 682 763 549 989 772 400 294 89(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.