32bit IEEE 754: Single Precision Floating Point Binary -> Float: 1 - 1000 0100 - 001 0010 0111 1111 1110 0011 The 32 Bit Single Precision IEEE 754 Binary Floating Point Standard Representation Number Converted and Written as a Base Ten Decimal System Number (Float)
1 - 1000 0100 - 001 0010 0111 1111 1110 0011: 32 bit single precision IEEE 754 binary floating point standard representation number converted to decimal system (base ten)
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:
1000 0100
The last 23 bits contain the mantissa:
001 0010 0111 1111 1110 0011
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
1000 0100(2) =
1 × 27 + 0 × 26 + 0 × 25 + 0 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 0 × 20 =
128 + 0 + 0 + 0 + 0 + 4 + 0 + 0 =
128 + 4 =
132(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 = 132 - 127 = 5
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).
001 0010 0111 1111 1110 0011(2) =
0 × 2-1 + 0 × 2-2 + 1 × 2-3 + 0 × 2-4 + 0 × 2-5 + 1 × 2-6 + 0 × 2-7 + 0 × 2-8 + 1 × 2-9 + 1 × 2-10 + 1 × 2-11 + 1 × 2-12 + 1 × 2-13 + 1 × 2-14 + 1 × 2-15 + 1 × 2-16 + 1 × 2-17 + 1 × 2-18 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 1 × 2-22 + 1 × 2-23 =
0 + 0 + 0.125 + 0 + 0 + 0.015 625 + 0 + 0 + 0.001 953 125 + 0.000 976 562 5 + 0.000 488 281 25 + 0.000 244 140 625 + 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 + 0.000 007 629 394 531 25 + 0.000 003 814 697 265 625 + 0 + 0 + 0 + 0.000 000 238 418 579 101 562 5 + 0.000 000 119 209 289 550 781 25 =
0.125 + 0.015 625 + 0.001 953 125 + 0.000 976 562 5 + 0.000 488 281 25 + 0.000 244 140 625 + 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 + 0.000 007 629 394 531 25 + 0.000 003 814 697 265 625 + 0.000 000 238 418 579 101 562 5 + 0.000 000 119 209 289 550 781 25 =
0.144 527 792 930 603 027 343 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 + 0.144 527 792 930 603 027 343 75) × 25 =
-1.144 527 792 930 603 027 343 75 × 25 =
-36.624 889 373 779 296 875
1 - 1000 0100 - 001 0010 0111 1111 1110 0011 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) = -36.624 889 373 779 296 875(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.
Convert 32 bit single precision IEEE 754 binary floating point standard numbers to base ten decimal system (float)
A number in 32 bit single precision IEEE 754 binary floating point standard representation...
... requires three building elements: the sign (it takes 1 bit and it's either 0 for positive or 1 for negative numbers), the exponent (8 bits) and the mantissa (23 bits)