0 - 011 0101 0111 - 1010 0000 0000 0000 0100 0000 0000 0000 0000 0000 0000 0011 1011 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
0 - 011 0101 0111 - 1010 0000 0000 0000 0100 0000 0000 0000 0000 0000 0000 0011 1011: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
0 - 011 0101 0111 - 1010 0000 0000 0000 0100 0000 0000 0000 0000 0000 0000 0011 1011, 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.
0
The next 11 bits contain the exponent:
011 0101 0111
The last 52 bits contain the mantissa:
1010 0000 0000 0000 0100 0000 0000 0000 0000 0000 0000 0011 1011
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
011 0101 0111(2) =
0 × 210 + 1 × 29 + 1 × 28 + 0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 0 × 23 + 1 × 22 + 1 × 21 + 1 × 20 =
0 + 512 + 256 + 0 + 64 + 0 + 16 + 0 + 4 + 2 + 1 =
512 + 256 + 64 + 16 + 4 + 2 + 1 =
855(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 = 855 - 1023 = -168
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 0000 0000 0000 0100 0000 0000 0000 0000 0000 0000 0011 1011(2) =
1 × 2-1 + 0 × 2-2 + 1 × 2-3 + 0 × 2-4 + 0 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 0 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 0 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 1 × 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 + 1 × 2-51 + 1 × 2-52 =
0.5 + 0 + 0.125 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 003 814 697 265 625 + 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 + 0.000 000 000 000 000 444 089 209 850 062 616 169 452 667 236 328 125 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.5 + 0.125 + 0.000 003 814 697 265 625 + 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 + 0.000 000 000 000 000 444 089 209 850 062 616 169 452 667 236 328 125 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.625 003 814 697 278 725 631 690 576 847 176 998 853 683 471 679 687 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)0 × (1 + 0.625 003 814 697 278 725 631 690 576 847 176 998 853 683 471 679 687 5) × 2-168 =
1.625 003 814 697 278 725 631 690 576 847 176 998 853 683 471 679 687 5 × 2-168 = ...
= 0.000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 004 343 252 849 688 084 187 579 007 233 213 585 074 011 119 722 956 863 556 759 890 771 177 172 619 735 372 698 379 640 200 550 281 872 037 707 842 376 095 435 777 071 356 985 706 840 347 916 113 387 327 641 248 703 002 929 687 5
0 - 011 0101 0111 - 1010 0000 0000 0000 0100 0000 0000 0000 0000 0000 0000 0011 1011, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = 0.000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 004 343 252 849 688 084 187 579 007 233 213 585 074 011 119 722 956 863 556 759 890 771 177 172 619 735 372 698 379 640 200 550 281 872 037 707 842 376 095 435 777 071 356 985 706 840 347 916 113 387 327 641 248 703 002 929 687 5(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.