1 - 101 0101 0000 - 1010 1010 1010 1000 0000 0000 0000 0000 0000 0000 0000 0011 1000 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 101 0101 0000 - 1010 1010 1010 1000 0000 0000 0000 0000 0000 0000 0000 0011 1000: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 101 0101 0000 - 1010 1010 1010 1000 0000 0000 0000 0000 0000 0000 0000 0011 1000, a 64 bit double 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 11 bits contain the exponent:
101 0101 0000
The last 52 bits contain the mantissa:
1010 1010 1010 1000 0000 0000 0000 0000 0000 0000 0000 0011 1000
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
101 0101 0000(2) =
1 × 210 + 0 × 29 + 1 × 28 + 0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
1,024 + 0 + 256 + 0 + 64 + 0 + 16 + 0 + 0 + 0 + 0 =
1,024 + 256 + 64 + 16 =
1,360(10)
3. Adjust the exponent.
Subtract the excess bits: 2(11 - 1) - 1 = 1023,
that is due to the 11 bit excess/bias notation.
The exponent, adjusted = 1,360 - 1023 = 337
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).
1010 1010 1010 1000 0000 0000 0000 0000 0000 0000 0000 0011 1000(2) =
1 × 2-1 + 0 × 2-2 + 1 × 2-3 + 0 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 0 × 2-8 + 1 × 2-9 + 0 × 2-10 + 1 × 2-11 + 0 × 2-12 + 1 × 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 + 0 × 2-22 + 0 × 2-23 + 0 × 2-24 + 0 × 2-25 + 0 × 2-26 + 0 × 2-27 + 0 × 2-28 + 0 × 2-29 + 0 × 2-30 + 0 × 2-31 + 0 × 2-32 + 0 × 2-33 + 0 × 2-34 + 0 × 2-35 + 0 × 2-36 + 0 × 2-37 + 0 × 2-38 + 0 × 2-39 + 0 × 2-40 + 0 × 2-41 + 0 × 2-42 + 0 × 2-43 + 0 × 2-44 + 0 × 2-45 + 0 × 2-46 + 1 × 2-47 + 1 × 2-48 + 1 × 2-49 + 0 × 2-50 + 0 × 2-51 + 0 × 2-52 =
0.5 + 0 + 0.125 + 0 + 0.031 25 + 0 + 0.007 812 5 + 0 + 0.001 953 125 + 0 + 0.000 488 281 25 + 0 + 0.000 122 070 312 5 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 007 105 427 357 601 001 858 711 242 675 781 25 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 + 0 + 0 + 0 =
0.5 + 0.125 + 0.031 25 + 0.007 812 5 + 0.001 953 125 + 0.000 488 281 25 + 0.000 122 070 312 5 + 0.000 000 000 000 007 105 427 357 601 001 858 711 242 675 781 25 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 =
0.666 625 976 562 512 434 497 875 801 753 252 744 674 682 617 187 5(10)
5. Put all the numbers into expression to calculate the double precision floating point decimal value:
(-1)Sign × (1 + Mantissa) × 2(Adjusted exponent) =
(-1)1 × (1 + 0.666 625 976 562 512 434 497 875 801 753 252 744 674 682 617 187 5) × 2337 =
-1.666 625 976 562 512 434 497 875 801 753 252 744 674 682 617 187 5 × 2337 = ...
= -466 602 096 022 854 446 941 682 570 175 821 408 006 468 625 245 646 787 482 446 926 579 570 337 905 167 618 987 895 109 700 749 885 440
1 - 101 0101 0000 - 1010 1010 1010 1000 0000 0000 0000 0000 0000 0000 0000 0011 1000, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -466 602 096 022 854 446 941 682 570 175 821 408 006 468 625 245 646 787 482 446 926 579 570 337 905 167 618 987 895 109 700 749 885 440(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.