0 - 111 1110 1000 - 0011 0000 1100 1001 0010 0011 1111 1001 0111 0100 0000 0000 1110 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
0 - 111 1110 1000 - 0011 0000 1100 1001 0010 0011 1111 1001 0111 0100 0000 0000 1110: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
0 - 111 1110 1000 - 0011 0000 1100 1001 0010 0011 1111 1001 0111 0100 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.
0
The next 11 bits contain the exponent:
111 1110 1000
The last 52 bits contain the mantissa:
0011 0000 1100 1001 0010 0011 1111 1001 0111 0100 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 1110 1000(2) =
1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 0 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
1,024 + 512 + 256 + 128 + 64 + 32 + 0 + 8 + 0 + 0 + 0 =
1,024 + 512 + 256 + 128 + 64 + 32 + 8 =
2,024(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 = 2,024 - 1023 = 1001
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).
0011 0000 1100 1001 0010 0011 1111 1001 0111 0100 0000 0000 1110(2) =
0 × 2-1 + 0 × 2-2 + 1 × 2-3 + 1 × 2-4 + 0 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 1 × 2-9 + 1 × 2-10 + 0 × 2-11 + 0 × 2-12 + 1 × 2-13 + 0 × 2-14 + 0 × 2-15 + 1 × 2-16 + 0 × 2-17 + 0 × 2-18 + 1 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 1 × 2-23 + 1 × 2-24 + 1 × 2-25 + 1 × 2-26 + 1 × 2-27 + 1 × 2-28 + 1 × 2-29 + 0 × 2-30 + 0 × 2-31 + 1 × 2-32 + 0 × 2-33 + 1 × 2-34 + 1 × 2-35 + 1 × 2-36 + 0 × 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 + 1 × 2-49 + 1 × 2-50 + 1 × 2-51 + 0 × 2-52 =
0 + 0 + 0.125 + 0.062 5 + 0 + 0 + 0 + 0 + 0.001 953 125 + 0.000 976 562 5 + 0 + 0 + 0.000 122 070 312 5 + 0 + 0 + 0.000 015 258 789 062 5 + 0 + 0 + 0.000 001 907 348 632 812 5 + 0 + 0 + 0 + 0.000 000 119 209 289 550 781 25 + 0.000 000 059 604 644 775 390 625 + 0.000 000 029 802 322 387 695 312 5 + 0.000 000 014 901 161 193 847 656 25 + 0.000 000 007 450 580 596 923 828 125 + 0.000 000 003 725 290 298 461 914 062 5 + 0.000 000 001 862 645 149 230 957 031 25 + 0 + 0 + 0.000 000 000 232 830 643 653 869 628 906 25 + 0 + 0.000 000 000 058 207 660 913 467 407 226 562 5 + 0.000 000 000 029 103 830 456 733 703 613 281 25 + 0.000 000 000 014 551 915 228 366 851 806 640 625 + 0 + 0.000 000 000 003 637 978 807 091 712 951 660 156 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 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 =
0.125 + 0.062 5 + 0.001 953 125 + 0.000 976 562 5 + 0.000 122 070 312 5 + 0.000 015 258 789 062 5 + 0.000 001 907 348 632 812 5 + 0.000 000 119 209 289 550 781 25 + 0.000 000 059 604 644 775 390 625 + 0.000 000 029 802 322 387 695 312 5 + 0.000 000 014 901 161 193 847 656 25 + 0.000 000 007 450 580 596 923 828 125 + 0.000 000 003 725 290 298 461 914 062 5 + 0.000 000 001 862 645 149 230 957 031 25 + 0.000 000 000 232 830 643 653 869 628 906 25 + 0.000 000 000 058 207 660 913 467 407 226 562 5 + 0.000 000 000 029 103 830 456 733 703 613 281 25 + 0.000 000 000 014 551 915 228 366 851 806 640 625 + 0.000 000 000 003 637 978 807 091 712 951 660 156 25 + 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 =
0.190 569 160 844 464 402 515 541 223 692 707 717 418 670 654 296 875(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)0 × (1 + 0.190 569 160 844 464 402 515 541 223 692 707 717 418 670 654 296 875) × 21001 =
1.190 569 160 844 464 402 515 541 223 692 707 717 418 670 654 296 875 × 21001 = ...
= 25 514 102 065 907 502 471 896 556 166 505 122 040 399 775 103 687 903 881 612 952 298 675 229 943 649 840 938 418 097 383 081 823 703 647 479 670 287 828 323 251 004 327 846 644 933 784 580 021 025 467 271 596 591 492 938 769 363 091 553 960 910 604 269 578 027 687 809 326 626 563 129 567 491 528 716 034 211 397 999 741 528 236 102 532 494 788 820 657 835 070 305 785 131 284 548 978 986 511 761 408
0 - 111 1110 1000 - 0011 0000 1100 1001 0010 0011 1111 1001 0111 0100 0000 0000 1110, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = 25 514 102 065 907 502 471 896 556 166 505 122 040 399 775 103 687 903 881 612 952 298 675 229 943 649 840 938 418 097 383 081 823 703 647 479 670 287 828 323 251 004 327 846 644 933 784 580 021 025 467 271 596 591 492 938 769 363 091 553 960 910 604 269 578 027 687 809 326 626 563 129 567 491 528 716 034 211 397 999 741 528 236 102 532 494 788 820 657 835 070 305 785 131 284 548 978 986 511 761 408(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.