1 - 111 0110 1000 - 1101 0100 1001 1001 0100 0010 0001 0110 0000 1000 0000 0000 1110 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 111 0110 1000 - 1101 0100 1001 1001 0100 0010 0001 0110 0000 1000 0000 0000 1110: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 111 0110 1000 - 1101 0100 1001 1001 0100 0010 0001 0110 0000 1000 0000 0000 1110, 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:
111 0110 1000
The last 52 bits contain the mantissa:
1101 0100 1001 1001 0100 0010 0001 0110 0000 1000 0000 0000 1110
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
111 0110 1000(2) =
1 × 210 + 1 × 29 + 1 × 28 + 0 × 27 + 1 × 26 + 1 × 25 + 0 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
1,024 + 512 + 256 + 0 + 64 + 32 + 0 + 8 + 0 + 0 + 0 =
1,024 + 512 + 256 + 64 + 32 + 8 =
1,896(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 = 1,896 - 1023 = 873
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 0100 1001 1001 0100 0010 0001 0110 0000 1000 0000 0000 1110(2) =
1 × 2-1 + 1 × 2-2 + 0 × 2-3 + 1 × 2-4 + 0 × 2-5 + 1 × 2-6 + 0 × 2-7 + 0 × 2-8 + 1 × 2-9 + 0 × 2-10 + 0 × 2-11 + 1 × 2-12 + 1 × 2-13 + 0 × 2-14 + 0 × 2-15 + 1 × 2-16 + 0 × 2-17 + 1 × 2-18 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 1 × 2-23 + 0 × 2-24 + 0 × 2-25 + 0 × 2-26 + 0 × 2-27 + 1 × 2-28 + 0 × 2-29 + 1 × 2-30 + 1 × 2-31 + 0 × 2-32 + 0 × 2-33 + 0 × 2-34 + 0 × 2-35 + 0 × 2-36 + 1 × 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 + 0 × 2-47 + 0 × 2-48 + 1 × 2-49 + 1 × 2-50 + 1 × 2-51 + 0 × 2-52 =
0.5 + 0.25 + 0 + 0.062 5 + 0 + 0.015 625 + 0 + 0 + 0.001 953 125 + 0 + 0 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0 + 0 + 0.000 015 258 789 062 5 + 0 + 0.000 003 814 697 265 625 + 0 + 0 + 0 + 0 + 0.000 000 119 209 289 550 781 25 + 0 + 0 + 0 + 0 + 0.000 000 003 725 290 298 461 914 062 5 + 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 + 0 + 0 + 0 + 0.000 000 000 007 275 957 614 183 425 903 320 312 5 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 + 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 =
0.5 + 0.25 + 0.062 5 + 0.015 625 + 0.001 953 125 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0.000 015 258 789 062 5 + 0.000 003 814 697 265 625 + 0.000 000 119 209 289 550 781 25 + 0.000 000 003 725 290 298 461 914 062 5 + 0.000 000 000 931 322 574 615 478 515 625 + 0.000 000 000 465 661 287 307 739 257 812 5 + 0.000 000 000 007 275 957 614 183 425 903 320 312 5 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 + 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 =
0.830 463 533 762 670 902 405 034 212 279 133 498 668 670 654 296 875(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 + 0.830 463 533 762 670 902 405 034 212 279 133 498 668 670 654 296 875) × 2873 =
-1.830 463 533 762 670 902 405 034 212 279 133 498 668 670 654 296 875 × 2873 = ...
= -115 278 229 037 533 184 998 071 372 817 784 146 088 356 357 121 778 425 365 557 981 731 454 807 032 641 246 636 452 367 452 552 213 439 422 130 740 684 649 377 069 104 495 866 483 799 088 398 985 178 658 847 915 790 232 652 440 857 095 741 826 329 524 921 830 079 823 443 050 408 989 039 682 346 799 557 440 113 628 775 326 681 013 163 818 947 182 592
1 - 111 0110 1000 - 1101 0100 1001 1001 0100 0010 0001 0110 0000 1000 0000 0000 1110, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -115 278 229 037 533 184 998 071 372 817 784 146 088 356 357 121 778 425 365 557 981 731 454 807 032 641 246 636 452 367 452 552 213 439 422 130 740 684 649 377 069 104 495 866 483 799 088 398 985 178 658 847 915 790 232 652 440 857 095 741 826 329 524 921 830 079 823 443 050 408 989 039 682 346 799 557 440 113 628 775 326 681 013 163 818 947 182 592(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.