0.000 020 830 729 321 671 205 134 999 154 509 660 615 85 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 020 830 729 321 671 205 134 999 154 509 660 615 85(10) to 64 bit double precision IEEE 754 binary floating point representation standard (1 bit for sign, 11 bits for exponent, 52 bits for mantissa)

What are the steps to convert decimal number
0.000 020 830 729 321 671 205 134 999 154 509 660 615 85(10) to 64 bit double precision IEEE 754 binary floating point representation (1 bit for sign, 11 bits for exponent, 52 bits for mantissa)

1. First, convert to binary (in base 2) the integer part: 0.
Divide the number repeatedly by 2.

Keep track of each remainder.

We stop when we get a quotient that is equal to zero.


  • division = quotient + remainder;
  • 0 ÷ 2 = 0 + 0;

2. Construct the base 2 representation of the integer part of the number.

Take all the remainders starting from the bottom of the list constructed above.

0(10) =


0(2)


3. Convert to binary (base 2) the fractional part: 0.000 020 830 729 321 671 205 134 999 154 509 660 615 85.

Multiply it repeatedly by 2.


Keep track of each integer part of the results.


Stop when we get a fractional part that is equal to zero.


  • #) multiplying = integer + fractional part;
  • 1) 0.000 020 830 729 321 671 205 134 999 154 509 660 615 85 × 2 = 0 + 0.000 041 661 458 643 342 410 269 998 309 019 321 231 7;
  • 2) 0.000 041 661 458 643 342 410 269 998 309 019 321 231 7 × 2 = 0 + 0.000 083 322 917 286 684 820 539 996 618 038 642 463 4;
  • 3) 0.000 083 322 917 286 684 820 539 996 618 038 642 463 4 × 2 = 0 + 0.000 166 645 834 573 369 641 079 993 236 077 284 926 8;
  • 4) 0.000 166 645 834 573 369 641 079 993 236 077 284 926 8 × 2 = 0 + 0.000 333 291 669 146 739 282 159 986 472 154 569 853 6;
  • 5) 0.000 333 291 669 146 739 282 159 986 472 154 569 853 6 × 2 = 0 + 0.000 666 583 338 293 478 564 319 972 944 309 139 707 2;
  • 6) 0.000 666 583 338 293 478 564 319 972 944 309 139 707 2 × 2 = 0 + 0.001 333 166 676 586 957 128 639 945 888 618 279 414 4;
  • 7) 0.001 333 166 676 586 957 128 639 945 888 618 279 414 4 × 2 = 0 + 0.002 666 333 353 173 914 257 279 891 777 236 558 828 8;
  • 8) 0.002 666 333 353 173 914 257 279 891 777 236 558 828 8 × 2 = 0 + 0.005 332 666 706 347 828 514 559 783 554 473 117 657 6;
  • 9) 0.005 332 666 706 347 828 514 559 783 554 473 117 657 6 × 2 = 0 + 0.010 665 333 412 695 657 029 119 567 108 946 235 315 2;
  • 10) 0.010 665 333 412 695 657 029 119 567 108 946 235 315 2 × 2 = 0 + 0.021 330 666 825 391 314 058 239 134 217 892 470 630 4;
  • 11) 0.021 330 666 825 391 314 058 239 134 217 892 470 630 4 × 2 = 0 + 0.042 661 333 650 782 628 116 478 268 435 784 941 260 8;
  • 12) 0.042 661 333 650 782 628 116 478 268 435 784 941 260 8 × 2 = 0 + 0.085 322 667 301 565 256 232 956 536 871 569 882 521 6;
  • 13) 0.085 322 667 301 565 256 232 956 536 871 569 882 521 6 × 2 = 0 + 0.170 645 334 603 130 512 465 913 073 743 139 765 043 2;
  • 14) 0.170 645 334 603 130 512 465 913 073 743 139 765 043 2 × 2 = 0 + 0.341 290 669 206 261 024 931 826 147 486 279 530 086 4;
  • 15) 0.341 290 669 206 261 024 931 826 147 486 279 530 086 4 × 2 = 0 + 0.682 581 338 412 522 049 863 652 294 972 559 060 172 8;
  • 16) 0.682 581 338 412 522 049 863 652 294 972 559 060 172 8 × 2 = 1 + 0.365 162 676 825 044 099 727 304 589 945 118 120 345 6;
  • 17) 0.365 162 676 825 044 099 727 304 589 945 118 120 345 6 × 2 = 0 + 0.730 325 353 650 088 199 454 609 179 890 236 240 691 2;
  • 18) 0.730 325 353 650 088 199 454 609 179 890 236 240 691 2 × 2 = 1 + 0.460 650 707 300 176 398 909 218 359 780 472 481 382 4;
  • 19) 0.460 650 707 300 176 398 909 218 359 780 472 481 382 4 × 2 = 0 + 0.921 301 414 600 352 797 818 436 719 560 944 962 764 8;
  • 20) 0.921 301 414 600 352 797 818 436 719 560 944 962 764 8 × 2 = 1 + 0.842 602 829 200 705 595 636 873 439 121 889 925 529 6;
  • 21) 0.842 602 829 200 705 595 636 873 439 121 889 925 529 6 × 2 = 1 + 0.685 205 658 401 411 191 273 746 878 243 779 851 059 2;
  • 22) 0.685 205 658 401 411 191 273 746 878 243 779 851 059 2 × 2 = 1 + 0.370 411 316 802 822 382 547 493 756 487 559 702 118 4;
  • 23) 0.370 411 316 802 822 382 547 493 756 487 559 702 118 4 × 2 = 0 + 0.740 822 633 605 644 765 094 987 512 975 119 404 236 8;
  • 24) 0.740 822 633 605 644 765 094 987 512 975 119 404 236 8 × 2 = 1 + 0.481 645 267 211 289 530 189 975 025 950 238 808 473 6;
  • 25) 0.481 645 267 211 289 530 189 975 025 950 238 808 473 6 × 2 = 0 + 0.963 290 534 422 579 060 379 950 051 900 477 616 947 2;
  • 26) 0.963 290 534 422 579 060 379 950 051 900 477 616 947 2 × 2 = 1 + 0.926 581 068 845 158 120 759 900 103 800 955 233 894 4;
  • 27) 0.926 581 068 845 158 120 759 900 103 800 955 233 894 4 × 2 = 1 + 0.853 162 137 690 316 241 519 800 207 601 910 467 788 8;
  • 28) 0.853 162 137 690 316 241 519 800 207 601 910 467 788 8 × 2 = 1 + 0.706 324 275 380 632 483 039 600 415 203 820 935 577 6;
  • 29) 0.706 324 275 380 632 483 039 600 415 203 820 935 577 6 × 2 = 1 + 0.412 648 550 761 264 966 079 200 830 407 641 871 155 2;
  • 30) 0.412 648 550 761 264 966 079 200 830 407 641 871 155 2 × 2 = 0 + 0.825 297 101 522 529 932 158 401 660 815 283 742 310 4;
  • 31) 0.825 297 101 522 529 932 158 401 660 815 283 742 310 4 × 2 = 1 + 0.650 594 203 045 059 864 316 803 321 630 567 484 620 8;
  • 32) 0.650 594 203 045 059 864 316 803 321 630 567 484 620 8 × 2 = 1 + 0.301 188 406 090 119 728 633 606 643 261 134 969 241 6;
  • 33) 0.301 188 406 090 119 728 633 606 643 261 134 969 241 6 × 2 = 0 + 0.602 376 812 180 239 457 267 213 286 522 269 938 483 2;
  • 34) 0.602 376 812 180 239 457 267 213 286 522 269 938 483 2 × 2 = 1 + 0.204 753 624 360 478 914 534 426 573 044 539 876 966 4;
  • 35) 0.204 753 624 360 478 914 534 426 573 044 539 876 966 4 × 2 = 0 + 0.409 507 248 720 957 829 068 853 146 089 079 753 932 8;
  • 36) 0.409 507 248 720 957 829 068 853 146 089 079 753 932 8 × 2 = 0 + 0.819 014 497 441 915 658 137 706 292 178 159 507 865 6;
  • 37) 0.819 014 497 441 915 658 137 706 292 178 159 507 865 6 × 2 = 1 + 0.638 028 994 883 831 316 275 412 584 356 319 015 731 2;
  • 38) 0.638 028 994 883 831 316 275 412 584 356 319 015 731 2 × 2 = 1 + 0.276 057 989 767 662 632 550 825 168 712 638 031 462 4;
  • 39) 0.276 057 989 767 662 632 550 825 168 712 638 031 462 4 × 2 = 0 + 0.552 115 979 535 325 265 101 650 337 425 276 062 924 8;
  • 40) 0.552 115 979 535 325 265 101 650 337 425 276 062 924 8 × 2 = 1 + 0.104 231 959 070 650 530 203 300 674 850 552 125 849 6;
  • 41) 0.104 231 959 070 650 530 203 300 674 850 552 125 849 6 × 2 = 0 + 0.208 463 918 141 301 060 406 601 349 701 104 251 699 2;
  • 42) 0.208 463 918 141 301 060 406 601 349 701 104 251 699 2 × 2 = 0 + 0.416 927 836 282 602 120 813 202 699 402 208 503 398 4;
  • 43) 0.416 927 836 282 602 120 813 202 699 402 208 503 398 4 × 2 = 0 + 0.833 855 672 565 204 241 626 405 398 804 417 006 796 8;
  • 44) 0.833 855 672 565 204 241 626 405 398 804 417 006 796 8 × 2 = 1 + 0.667 711 345 130 408 483 252 810 797 608 834 013 593 6;
  • 45) 0.667 711 345 130 408 483 252 810 797 608 834 013 593 6 × 2 = 1 + 0.335 422 690 260 816 966 505 621 595 217 668 027 187 2;
  • 46) 0.335 422 690 260 816 966 505 621 595 217 668 027 187 2 × 2 = 0 + 0.670 845 380 521 633 933 011 243 190 435 336 054 374 4;
  • 47) 0.670 845 380 521 633 933 011 243 190 435 336 054 374 4 × 2 = 1 + 0.341 690 761 043 267 866 022 486 380 870 672 108 748 8;
  • 48) 0.341 690 761 043 267 866 022 486 380 870 672 108 748 8 × 2 = 0 + 0.683 381 522 086 535 732 044 972 761 741 344 217 497 6;
  • 49) 0.683 381 522 086 535 732 044 972 761 741 344 217 497 6 × 2 = 1 + 0.366 763 044 173 071 464 089 945 523 482 688 434 995 2;
  • 50) 0.366 763 044 173 071 464 089 945 523 482 688 434 995 2 × 2 = 0 + 0.733 526 088 346 142 928 179 891 046 965 376 869 990 4;
  • 51) 0.733 526 088 346 142 928 179 891 046 965 376 869 990 4 × 2 = 1 + 0.467 052 176 692 285 856 359 782 093 930 753 739 980 8;
  • 52) 0.467 052 176 692 285 856 359 782 093 930 753 739 980 8 × 2 = 0 + 0.934 104 353 384 571 712 719 564 187 861 507 479 961 6;
  • 53) 0.934 104 353 384 571 712 719 564 187 861 507 479 961 6 × 2 = 1 + 0.868 208 706 769 143 425 439 128 375 723 014 959 923 2;
  • 54) 0.868 208 706 769 143 425 439 128 375 723 014 959 923 2 × 2 = 1 + 0.736 417 413 538 286 850 878 256 751 446 029 919 846 4;
  • 55) 0.736 417 413 538 286 850 878 256 751 446 029 919 846 4 × 2 = 1 + 0.472 834 827 076 573 701 756 513 502 892 059 839 692 8;
  • 56) 0.472 834 827 076 573 701 756 513 502 892 059 839 692 8 × 2 = 0 + 0.945 669 654 153 147 403 513 027 005 784 119 679 385 6;
  • 57) 0.945 669 654 153 147 403 513 027 005 784 119 679 385 6 × 2 = 1 + 0.891 339 308 306 294 807 026 054 011 568 239 358 771 2;
  • 58) 0.891 339 308 306 294 807 026 054 011 568 239 358 771 2 × 2 = 1 + 0.782 678 616 612 589 614 052 108 023 136 478 717 542 4;
  • 59) 0.782 678 616 612 589 614 052 108 023 136 478 717 542 4 × 2 = 1 + 0.565 357 233 225 179 228 104 216 046 272 957 435 084 8;
  • 60) 0.565 357 233 225 179 228 104 216 046 272 957 435 084 8 × 2 = 1 + 0.130 714 466 450 358 456 208 432 092 545 914 870 169 6;
  • 61) 0.130 714 466 450 358 456 208 432 092 545 914 870 169 6 × 2 = 0 + 0.261 428 932 900 716 912 416 864 185 091 829 740 339 2;
  • 62) 0.261 428 932 900 716 912 416 864 185 091 829 740 339 2 × 2 = 0 + 0.522 857 865 801 433 824 833 728 370 183 659 480 678 4;
  • 63) 0.522 857 865 801 433 824 833 728 370 183 659 480 678 4 × 2 = 1 + 0.045 715 731 602 867 649 667 456 740 367 318 961 356 8;
  • 64) 0.045 715 731 602 867 649 667 456 740 367 318 961 356 8 × 2 = 0 + 0.091 431 463 205 735 299 334 913 480 734 637 922 713 6;
  • 65) 0.091 431 463 205 735 299 334 913 480 734 637 922 713 6 × 2 = 0 + 0.182 862 926 411 470 598 669 826 961 469 275 845 427 2;
  • 66) 0.182 862 926 411 470 598 669 826 961 469 275 845 427 2 × 2 = 0 + 0.365 725 852 822 941 197 339 653 922 938 551 690 854 4;
  • 67) 0.365 725 852 822 941 197 339 653 922 938 551 690 854 4 × 2 = 0 + 0.731 451 705 645 882 394 679 307 845 877 103 381 708 8;
  • 68) 0.731 451 705 645 882 394 679 307 845 877 103 381 708 8 × 2 = 1 + 0.462 903 411 291 764 789 358 615 691 754 206 763 417 6;

We didn't get any fractional part that was equal to zero. But we had enough iterations (over Mantissa limit) and at least one integer that was different from zero => FULL STOP (Losing precision - the converted number we get in the end will be just a very good approximation of the initial one).


4. Construct the base 2 representation of the fractional part of the number.

Take all the integer parts of the multiplying operations, starting from the top of the constructed list above:


0.000 020 830 729 321 671 205 134 999 154 509 660 615 85(10) =


0.0000 0000 0000 0001 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2)

5. Positive number before normalization:

0.000 020 830 729 321 671 205 134 999 154 509 660 615 85(10) =


0.0000 0000 0000 0001 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2)

6. Normalize the binary representation of the number.

Shift the decimal mark 16 positions to the right, so that only one non zero digit remains to the left of it:


0.000 020 830 729 321 671 205 134 999 154 509 660 615 85(10) =


0.0000 0000 0000 0001 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2) =


0.0000 0000 0000 0001 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2) × 20 =


1.0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001(2) × 2-16


7. Up to this moment, there are the following elements that would feed into the 64 bit double precision IEEE 754 binary floating point representation:

Sign 0 (a positive number)


Exponent (unadjusted): -16


Mantissa (not normalized):
1.0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001


8. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


Exponent (unadjusted) + 2(11-1) - 1 =


-16 + 2(11-1) - 1 =


(-16 + 1 023)(10) =


1 007(10)


9. Convert the adjusted exponent from the decimal (base 10) to 11 bit binary.

Use the same technique of repeatedly dividing by 2:


  • division = quotient + remainder;
  • 1 007 ÷ 2 = 503 + 1;
  • 503 ÷ 2 = 251 + 1;
  • 251 ÷ 2 = 125 + 1;
  • 125 ÷ 2 = 62 + 1;
  • 62 ÷ 2 = 31 + 0;
  • 31 ÷ 2 = 15 + 1;
  • 15 ÷ 2 = 7 + 1;
  • 7 ÷ 2 = 3 + 1;
  • 3 ÷ 2 = 1 + 1;
  • 1 ÷ 2 = 0 + 1;

10. Construct the base 2 representation of the adjusted exponent.

Take all the remainders starting from the bottom of the list constructed above.


Exponent (adjusted) =


1007(10) =


011 1110 1111(2)


11. Normalize the mantissa.

a) Remove the leading (the leftmost) bit, since it's allways 1, and the decimal point, if the case.


b) Adjust its length to 52 bits, only if necessary (not the case here).


Mantissa (normalized) =


1. 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001 =


0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001


12. The three elements that make up the number's 64 bit double precision IEEE 754 binary floating point representation:

Sign (1 bit) =
0 (a positive number)


Exponent (11 bits) =
011 1110 1111


Mantissa (52 bits) =
0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001


Decimal number 0.000 020 830 729 321 671 205 134 999 154 509 660 615 85 converted to 64 bit double precision IEEE 754 binary floating point representation:

0 - 011 1110 1111 - 0101 1101 0111 1011 0100 1101 0001 1010 1010 1110 1111 0010 0001


How to convert numbers from the decimal system (base ten) to 64 bit double precision IEEE 754 binary floating point standard

Follow the steps below to convert a base 10 decimal number to 64 bit double precision IEEE 754 binary floating point:

  • 1. If the number to be converted is negative, start with its the positive version.
  • 2. First convert the integer part. Divide repeatedly by 2 the positive representation of the integer number that is to be converted to binary, until we get a quotient that is equal to zero, keeping track of each remainder.
  • 3. Construct the base 2 representation of the positive integer part of the number, by taking all the remainders from the previous operations, starting from the bottom of the list constructed above. Thus, the last remainder of the divisions becomes the first symbol (the leftmost) of the base two number, while the first remainder becomes the last symbol (the rightmost).
  • 4. Then convert the fractional part. Multiply the number repeatedly by 2, until we get a fractional part that is equal to zero, keeping track of each integer part of the results.
  • 5. Construct the base 2 representation of the fractional part of the number, by taking all the integer parts of the multiplying operations, starting from the top of the list constructed above (they should appear in the binary representation, from left to right, in the order they have been calculated).
  • 6. Normalize the binary representation of the number, shifting the decimal mark (the decimal point) "n" positions either to the left, or to the right, so that only one non zero digit remains to the left of the decimal mark.
  • 7. Adjust the exponent in 11 bit excess/bias notation and then convert it from decimal (base 10) to 11 bit binary, by using the same technique of repeatedly dividing by 2, as shown above:
    Exponent (adjusted) = Exponent (unadjusted) + 2(11-1) - 1
  • 8. Normalize mantissa, remove the leading (leftmost) bit, since it's allways '1' (and the decimal mark, if the case) and adjust its length to 52 bits, either by removing the excess bits from the right (losing precision...) or by adding extra bits set on '0' to the right.
  • 9. Sign (it takes 1 bit) is either 1 for a negative or 0 for a positive number.

Example: convert the negative number -31.640 215 from the decimal system (base ten) to 64 bit double precision IEEE 754 binary floating point:

  • 1. Start with the positive version of the number:

    |-31.640 215| = 31.640 215

  • 2. First convert the integer part, 31. Divide it repeatedly by 2, keeping track of each remainder, until we get a quotient that is equal to zero:
    • division = quotient + remainder;
    • 31 ÷ 2 = 15 + 1;
    • 15 ÷ 2 = 7 + 1;
    • 7 ÷ 2 = 3 + 1;
    • 3 ÷ 2 = 1 + 1;
    • 1 ÷ 2 = 0 + 1;
    • We have encountered a quotient that is ZERO => FULL STOP
  • 3. Construct the base 2 representation of the integer part of the number by taking all the remainders of the previous dividing operations, starting from the bottom of the list constructed above:

    31(10) = 1 1111(2)

  • 4. Then, convert the fractional part, 0.640 215. Multiply repeatedly by 2, keeping track of each integer part of the results, until we get a fractional part that is equal to zero:
    • #) multiplying = integer + fractional part;
    • 1) 0.640 215 × 2 = 1 + 0.280 43;
    • 2) 0.280 43 × 2 = 0 + 0.560 86;
    • 3) 0.560 86 × 2 = 1 + 0.121 72;
    • 4) 0.121 72 × 2 = 0 + 0.243 44;
    • 5) 0.243 44 × 2 = 0 + 0.486 88;
    • 6) 0.486 88 × 2 = 0 + 0.973 76;
    • 7) 0.973 76 × 2 = 1 + 0.947 52;
    • 8) 0.947 52 × 2 = 1 + 0.895 04;
    • 9) 0.895 04 × 2 = 1 + 0.790 08;
    • 10) 0.790 08 × 2 = 1 + 0.580 16;
    • 11) 0.580 16 × 2 = 1 + 0.160 32;
    • 12) 0.160 32 × 2 = 0 + 0.320 64;
    • 13) 0.320 64 × 2 = 0 + 0.641 28;
    • 14) 0.641 28 × 2 = 1 + 0.282 56;
    • 15) 0.282 56 × 2 = 0 + 0.565 12;
    • 16) 0.565 12 × 2 = 1 + 0.130 24;
    • 17) 0.130 24 × 2 = 0 + 0.260 48;
    • 18) 0.260 48 × 2 = 0 + 0.520 96;
    • 19) 0.520 96 × 2 = 1 + 0.041 92;
    • 20) 0.041 92 × 2 = 0 + 0.083 84;
    • 21) 0.083 84 × 2 = 0 + 0.167 68;
    • 22) 0.167 68 × 2 = 0 + 0.335 36;
    • 23) 0.335 36 × 2 = 0 + 0.670 72;
    • 24) 0.670 72 × 2 = 1 + 0.341 44;
    • 25) 0.341 44 × 2 = 0 + 0.682 88;
    • 26) 0.682 88 × 2 = 1 + 0.365 76;
    • 27) 0.365 76 × 2 = 0 + 0.731 52;
    • 28) 0.731 52 × 2 = 1 + 0.463 04;
    • 29) 0.463 04 × 2 = 0 + 0.926 08;
    • 30) 0.926 08 × 2 = 1 + 0.852 16;
    • 31) 0.852 16 × 2 = 1 + 0.704 32;
    • 32) 0.704 32 × 2 = 1 + 0.408 64;
    • 33) 0.408 64 × 2 = 0 + 0.817 28;
    • 34) 0.817 28 × 2 = 1 + 0.634 56;
    • 35) 0.634 56 × 2 = 1 + 0.269 12;
    • 36) 0.269 12 × 2 = 0 + 0.538 24;
    • 37) 0.538 24 × 2 = 1 + 0.076 48;
    • 38) 0.076 48 × 2 = 0 + 0.152 96;
    • 39) 0.152 96 × 2 = 0 + 0.305 92;
    • 40) 0.305 92 × 2 = 0 + 0.611 84;
    • 41) 0.611 84 × 2 = 1 + 0.223 68;
    • 42) 0.223 68 × 2 = 0 + 0.447 36;
    • 43) 0.447 36 × 2 = 0 + 0.894 72;
    • 44) 0.894 72 × 2 = 1 + 0.789 44;
    • 45) 0.789 44 × 2 = 1 + 0.578 88;
    • 46) 0.578 88 × 2 = 1 + 0.157 76;
    • 47) 0.157 76 × 2 = 0 + 0.315 52;
    • 48) 0.315 52 × 2 = 0 + 0.631 04;
    • 49) 0.631 04 × 2 = 1 + 0.262 08;
    • 50) 0.262 08 × 2 = 0 + 0.524 16;
    • 51) 0.524 16 × 2 = 1 + 0.048 32;
    • 52) 0.048 32 × 2 = 0 + 0.096 64;
    • 53) 0.096 64 × 2 = 0 + 0.193 28;
    • We didn't get any fractional part that was equal to zero. But we had enough iterations (over Mantissa limit = 52) and at least one integer part that was different from zero => FULL STOP (losing precision...).
  • 5. Construct the base 2 representation of the fractional part of the number, by taking all the integer parts of the previous multiplying operations, starting from the top of the constructed list above:

    0.640 215(10) = 0.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2)

  • 6. Summarizing - the positive number before normalization:

    31.640 215(10) = 1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2)

  • 7. Normalize the binary representation of the number, shifting the decimal mark 4 positions to the left so that only one non-zero digit stays to the left of the decimal mark:

    31.640 215(10) =
    1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) =
    1 1111.1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) × 20 =
    1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0(2) × 24

  • 8. Up to this moment, there are the following elements that would feed into the 64 bit double precision IEEE 754 binary floating point representation:

    Sign: 1 (a negative number)

    Exponent (unadjusted): 4

    Mantissa (not-normalized): 1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0

  • 9. Adjust the exponent in 11 bit excess/bias notation and then convert it from decimal (base 10) to 11 bit binary (base 2), by using the same technique of repeatedly dividing it by 2, as shown above:

    Exponent (adjusted) = Exponent (unadjusted) + 2(11-1) - 1 = (4 + 1023)(10) = 1027(10) =
    100 0000 0011(2)

  • 10. Normalize mantissa, remove the leading (leftmost) bit, since it's allways '1' (and the decimal sign) and adjust its length to 52 bits, by removing the excess bits, from the right (losing precision...):

    Mantissa (not-normalized): 1.1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100 1010 0

    Mantissa (normalized): 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100

  • Conclusion:

    Sign (1 bit) = 1 (a negative number)

    Exponent (8 bits) = 100 0000 0011

    Mantissa (52 bits) = 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100

  • Number -31.640 215, converted from decimal system (base 10) to 64 bit double precision IEEE 754 binary floating point =
    1 - 100 0000 0011 - 1111 1010 0011 1110 0101 0010 0001 0101 0111 0110 1000 1001 1100