0 - 110 1111 1011 - 1101 1010 0100 1000 1100 1110 0100 0110 1000 1100 0000 0000 0111 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
0 - 110 1111 1011 - 1101 1010 0100 1000 1100 1110 0100 0110 1000 1100 0000 0000 0111: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
0 - 110 1111 1011 - 1101 1010 0100 1000 1100 1110 0100 0110 1000 1100 0000 0000 0111, 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:
110 1111 1011
The last 52 bits contain the mantissa:
1101 1010 0100 1000 1100 1110 0100 0110 1000 1100 0000 0000 0111
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
110 1111 1011(2) =
1 × 210 + 1 × 29 + 0 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 1 × 21 + 1 × 20 =
1,024 + 512 + 0 + 128 + 64 + 32 + 16 + 8 + 0 + 2 + 1 =
1,024 + 512 + 128 + 64 + 32 + 16 + 8 + 2 + 1 =
1,787(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 = 1,787 - 1023 = 764
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).
1101 1010 0100 1000 1100 1110 0100 0110 1000 1100 0000 0000 0111(2) =
1 × 2-1 + 1 × 2-2 + 0 × 2-3 + 1 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 0 × 2-8 + 0 × 2-9 + 1 × 2-10 + 0 × 2-11 + 0 × 2-12 + 1 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 1 × 2-17 + 1 × 2-18 + 0 × 2-19 + 0 × 2-20 + 1 × 2-21 + 1 × 2-22 + 1 × 2-23 + 0 × 2-24 + 0 × 2-25 + 1 × 2-26 + 0 × 2-27 + 0 × 2-28 + 0 × 2-29 + 1 × 2-30 + 1 × 2-31 + 0 × 2-32 + 1 × 2-33 + 0 × 2-34 + 0 × 2-35 + 0 × 2-36 + 1 × 2-37 + 1 × 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 + 0 × 2-47 + 0 × 2-48 + 0 × 2-49 + 1 × 2-50 + 1 × 2-51 + 1 × 2-52 =
0.5 + 0.25 + 0 + 0.062 5 + 0.031 25 + 0 + 0.007 812 5 + 0 + 0 + 0.000 976 562 5 + 0 + 0 + 0.000 122 070 312 5 + 0 + 0 + 0 + 0.000 007 629 394 531 25 + 0.000 003 814 697 265 625 + 0 + 0 + 0.000 000 476 837 158 203 125 + 0.000 000 238 418 579 101 562 5 + 0.000 000 119 209 289 550 781 25 + 0 + 0 + 0.000 000 014 901 161 193 847 656 25 + 0 + 0 + 0 + 0.000 000 000 931 322 574 615 478 515 625 + 0.000 000 000 465 661 287 307 739 257 812 5 + 0 + 0.000 000 000 116 415 321 826 934 814 453 125 + 0 + 0 + 0 + 0.000 000 000 007 275 957 614 183 425 903 320 312 5 + 0.000 000 000 003 637 978 807 091 712 951 660 156 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 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 + 0.25 + 0.062 5 + 0.031 25 + 0.007 812 5 + 0.000 976 562 5 + 0.000 122 070 312 5 + 0.000 007 629 394 531 25 + 0.000 003 814 697 265 625 + 0.000 000 476 837 158 203 125 + 0.000 000 238 418 579 101 562 5 + 0.000 000 119 209 289 550 781 25 + 0.000 000 014 901 161 193 847 656 25 + 0.000 000 000 931 322 574 615 478 515 625 + 0.000 000 000 465 661 287 307 739 257 812 5 + 0.000 000 000 116 415 321 826 934 814 453 125 + 0.000 000 000 007 275 957 614 183 425 903 320 312 5 + 0.000 000 000 003 637 978 807 091 712 951 660 156 25 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 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 =
0.852 673 427 794 799 598 800 068 451 964 762 061 834 335 327 148 437 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 + 0.852 673 427 794 799 598 800 068 451 964 762 061 834 335 327 148 437 5) × 2764 =
1.852 673 427 794 799 598 800 068 451 964 762 061 834 335 327 148 437 5 × 2764 = ...
= 179 769 313 486 012 343 393 901 980 498 016 394 830 869 931 232 256 776 436 462 872 840 730 321 089 879 326 863 732 568 404 533 061 955 375 251 152 139 566 037 559 693 580 074 960 260 217 525 422 542 956 746 430 402 688 505 899 736 859 106 442 491 925 735 962 101 538 007 970 886 860 427 598 690 342 928 384
0 - 110 1111 1011 - 1101 1010 0100 1000 1100 1110 0100 0110 1000 1100 0000 0000 0111, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = 179 769 313 486 012 343 393 901 980 498 016 394 830 869 931 232 256 776 436 462 872 840 730 321 089 879 326 863 732 568 404 533 061 955 375 251 152 139 566 037 559 693 580 074 960 260 217 525 422 542 956 746 430 402 688 505 899 736 859 106 442 491 925 735 962 101 538 007 970 886 860 427 598 690 342 928 384(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.