0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8(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
0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8(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: 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8.

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) 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8 × 2 = 0 + 0.000 000 000 007 269 999 999 999 999 516 522 114 064 601 356 670 305 6;
  • 2) 0.000 000 000 007 269 999 999 999 999 516 522 114 064 601 356 670 305 6 × 2 = 0 + 0.000 000 000 014 539 999 999 999 999 033 044 228 129 202 713 340 611 2;
  • 3) 0.000 000 000 014 539 999 999 999 999 033 044 228 129 202 713 340 611 2 × 2 = 0 + 0.000 000 000 029 079 999 999 999 998 066 088 456 258 405 426 681 222 4;
  • 4) 0.000 000 000 029 079 999 999 999 998 066 088 456 258 405 426 681 222 4 × 2 = 0 + 0.000 000 000 058 159 999 999 999 996 132 176 912 516 810 853 362 444 8;
  • 5) 0.000 000 000 058 159 999 999 999 996 132 176 912 516 810 853 362 444 8 × 2 = 0 + 0.000 000 000 116 319 999 999 999 992 264 353 825 033 621 706 724 889 6;
  • 6) 0.000 000 000 116 319 999 999 999 992 264 353 825 033 621 706 724 889 6 × 2 = 0 + 0.000 000 000 232 639 999 999 999 984 528 707 650 067 243 413 449 779 2;
  • 7) 0.000 000 000 232 639 999 999 999 984 528 707 650 067 243 413 449 779 2 × 2 = 0 + 0.000 000 000 465 279 999 999 999 969 057 415 300 134 486 826 899 558 4;
  • 8) 0.000 000 000 465 279 999 999 999 969 057 415 300 134 486 826 899 558 4 × 2 = 0 + 0.000 000 000 930 559 999 999 999 938 114 830 600 268 973 653 799 116 8;
  • 9) 0.000 000 000 930 559 999 999 999 938 114 830 600 268 973 653 799 116 8 × 2 = 0 + 0.000 000 001 861 119 999 999 999 876 229 661 200 537 947 307 598 233 6;
  • 10) 0.000 000 001 861 119 999 999 999 876 229 661 200 537 947 307 598 233 6 × 2 = 0 + 0.000 000 003 722 239 999 999 999 752 459 322 401 075 894 615 196 467 2;
  • 11) 0.000 000 003 722 239 999 999 999 752 459 322 401 075 894 615 196 467 2 × 2 = 0 + 0.000 000 007 444 479 999 999 999 504 918 644 802 151 789 230 392 934 4;
  • 12) 0.000 000 007 444 479 999 999 999 504 918 644 802 151 789 230 392 934 4 × 2 = 0 + 0.000 000 014 888 959 999 999 999 009 837 289 604 303 578 460 785 868 8;
  • 13) 0.000 000 014 888 959 999 999 999 009 837 289 604 303 578 460 785 868 8 × 2 = 0 + 0.000 000 029 777 919 999 999 998 019 674 579 208 607 156 921 571 737 6;
  • 14) 0.000 000 029 777 919 999 999 998 019 674 579 208 607 156 921 571 737 6 × 2 = 0 + 0.000 000 059 555 839 999 999 996 039 349 158 417 214 313 843 143 475 2;
  • 15) 0.000 000 059 555 839 999 999 996 039 349 158 417 214 313 843 143 475 2 × 2 = 0 + 0.000 000 119 111 679 999 999 992 078 698 316 834 428 627 686 286 950 4;
  • 16) 0.000 000 119 111 679 999 999 992 078 698 316 834 428 627 686 286 950 4 × 2 = 0 + 0.000 000 238 223 359 999 999 984 157 396 633 668 857 255 372 573 900 8;
  • 17) 0.000 000 238 223 359 999 999 984 157 396 633 668 857 255 372 573 900 8 × 2 = 0 + 0.000 000 476 446 719 999 999 968 314 793 267 337 714 510 745 147 801 6;
  • 18) 0.000 000 476 446 719 999 999 968 314 793 267 337 714 510 745 147 801 6 × 2 = 0 + 0.000 000 952 893 439 999 999 936 629 586 534 675 429 021 490 295 603 2;
  • 19) 0.000 000 952 893 439 999 999 936 629 586 534 675 429 021 490 295 603 2 × 2 = 0 + 0.000 001 905 786 879 999 999 873 259 173 069 350 858 042 980 591 206 4;
  • 20) 0.000 001 905 786 879 999 999 873 259 173 069 350 858 042 980 591 206 4 × 2 = 0 + 0.000 003 811 573 759 999 999 746 518 346 138 701 716 085 961 182 412 8;
  • 21) 0.000 003 811 573 759 999 999 746 518 346 138 701 716 085 961 182 412 8 × 2 = 0 + 0.000 007 623 147 519 999 999 493 036 692 277 403 432 171 922 364 825 6;
  • 22) 0.000 007 623 147 519 999 999 493 036 692 277 403 432 171 922 364 825 6 × 2 = 0 + 0.000 015 246 295 039 999 998 986 073 384 554 806 864 343 844 729 651 2;
  • 23) 0.000 015 246 295 039 999 998 986 073 384 554 806 864 343 844 729 651 2 × 2 = 0 + 0.000 030 492 590 079 999 997 972 146 769 109 613 728 687 689 459 302 4;
  • 24) 0.000 030 492 590 079 999 997 972 146 769 109 613 728 687 689 459 302 4 × 2 = 0 + 0.000 060 985 180 159 999 995 944 293 538 219 227 457 375 378 918 604 8;
  • 25) 0.000 060 985 180 159 999 995 944 293 538 219 227 457 375 378 918 604 8 × 2 = 0 + 0.000 121 970 360 319 999 991 888 587 076 438 454 914 750 757 837 209 6;
  • 26) 0.000 121 970 360 319 999 991 888 587 076 438 454 914 750 757 837 209 6 × 2 = 0 + 0.000 243 940 720 639 999 983 777 174 152 876 909 829 501 515 674 419 2;
  • 27) 0.000 243 940 720 639 999 983 777 174 152 876 909 829 501 515 674 419 2 × 2 = 0 + 0.000 487 881 441 279 999 967 554 348 305 753 819 659 003 031 348 838 4;
  • 28) 0.000 487 881 441 279 999 967 554 348 305 753 819 659 003 031 348 838 4 × 2 = 0 + 0.000 975 762 882 559 999 935 108 696 611 507 639 318 006 062 697 676 8;
  • 29) 0.000 975 762 882 559 999 935 108 696 611 507 639 318 006 062 697 676 8 × 2 = 0 + 0.001 951 525 765 119 999 870 217 393 223 015 278 636 012 125 395 353 6;
  • 30) 0.001 951 525 765 119 999 870 217 393 223 015 278 636 012 125 395 353 6 × 2 = 0 + 0.003 903 051 530 239 999 740 434 786 446 030 557 272 024 250 790 707 2;
  • 31) 0.003 903 051 530 239 999 740 434 786 446 030 557 272 024 250 790 707 2 × 2 = 0 + 0.007 806 103 060 479 999 480 869 572 892 061 114 544 048 501 581 414 4;
  • 32) 0.007 806 103 060 479 999 480 869 572 892 061 114 544 048 501 581 414 4 × 2 = 0 + 0.015 612 206 120 959 998 961 739 145 784 122 229 088 097 003 162 828 8;
  • 33) 0.015 612 206 120 959 998 961 739 145 784 122 229 088 097 003 162 828 8 × 2 = 0 + 0.031 224 412 241 919 997 923 478 291 568 244 458 176 194 006 325 657 6;
  • 34) 0.031 224 412 241 919 997 923 478 291 568 244 458 176 194 006 325 657 6 × 2 = 0 + 0.062 448 824 483 839 995 846 956 583 136 488 916 352 388 012 651 315 2;
  • 35) 0.062 448 824 483 839 995 846 956 583 136 488 916 352 388 012 651 315 2 × 2 = 0 + 0.124 897 648 967 679 991 693 913 166 272 977 832 704 776 025 302 630 4;
  • 36) 0.124 897 648 967 679 991 693 913 166 272 977 832 704 776 025 302 630 4 × 2 = 0 + 0.249 795 297 935 359 983 387 826 332 545 955 665 409 552 050 605 260 8;
  • 37) 0.249 795 297 935 359 983 387 826 332 545 955 665 409 552 050 605 260 8 × 2 = 0 + 0.499 590 595 870 719 966 775 652 665 091 911 330 819 104 101 210 521 6;
  • 38) 0.499 590 595 870 719 966 775 652 665 091 911 330 819 104 101 210 521 6 × 2 = 0 + 0.999 181 191 741 439 933 551 305 330 183 822 661 638 208 202 421 043 2;
  • 39) 0.999 181 191 741 439 933 551 305 330 183 822 661 638 208 202 421 043 2 × 2 = 1 + 0.998 362 383 482 879 867 102 610 660 367 645 323 276 416 404 842 086 4;
  • 40) 0.998 362 383 482 879 867 102 610 660 367 645 323 276 416 404 842 086 4 × 2 = 1 + 0.996 724 766 965 759 734 205 221 320 735 290 646 552 832 809 684 172 8;
  • 41) 0.996 724 766 965 759 734 205 221 320 735 290 646 552 832 809 684 172 8 × 2 = 1 + 0.993 449 533 931 519 468 410 442 641 470 581 293 105 665 619 368 345 6;
  • 42) 0.993 449 533 931 519 468 410 442 641 470 581 293 105 665 619 368 345 6 × 2 = 1 + 0.986 899 067 863 038 936 820 885 282 941 162 586 211 331 238 736 691 2;
  • 43) 0.986 899 067 863 038 936 820 885 282 941 162 586 211 331 238 736 691 2 × 2 = 1 + 0.973 798 135 726 077 873 641 770 565 882 325 172 422 662 477 473 382 4;
  • 44) 0.973 798 135 726 077 873 641 770 565 882 325 172 422 662 477 473 382 4 × 2 = 1 + 0.947 596 271 452 155 747 283 541 131 764 650 344 845 324 954 946 764 8;
  • 45) 0.947 596 271 452 155 747 283 541 131 764 650 344 845 324 954 946 764 8 × 2 = 1 + 0.895 192 542 904 311 494 567 082 263 529 300 689 690 649 909 893 529 6;
  • 46) 0.895 192 542 904 311 494 567 082 263 529 300 689 690 649 909 893 529 6 × 2 = 1 + 0.790 385 085 808 622 989 134 164 527 058 601 379 381 299 819 787 059 2;
  • 47) 0.790 385 085 808 622 989 134 164 527 058 601 379 381 299 819 787 059 2 × 2 = 1 + 0.580 770 171 617 245 978 268 329 054 117 202 758 762 599 639 574 118 4;
  • 48) 0.580 770 171 617 245 978 268 329 054 117 202 758 762 599 639 574 118 4 × 2 = 1 + 0.161 540 343 234 491 956 536 658 108 234 405 517 525 199 279 148 236 8;
  • 49) 0.161 540 343 234 491 956 536 658 108 234 405 517 525 199 279 148 236 8 × 2 = 0 + 0.323 080 686 468 983 913 073 316 216 468 811 035 050 398 558 296 473 6;
  • 50) 0.323 080 686 468 983 913 073 316 216 468 811 035 050 398 558 296 473 6 × 2 = 0 + 0.646 161 372 937 967 826 146 632 432 937 622 070 100 797 116 592 947 2;
  • 51) 0.646 161 372 937 967 826 146 632 432 937 622 070 100 797 116 592 947 2 × 2 = 1 + 0.292 322 745 875 935 652 293 264 865 875 244 140 201 594 233 185 894 4;
  • 52) 0.292 322 745 875 935 652 293 264 865 875 244 140 201 594 233 185 894 4 × 2 = 0 + 0.584 645 491 751 871 304 586 529 731 750 488 280 403 188 466 371 788 8;
  • 53) 0.584 645 491 751 871 304 586 529 731 750 488 280 403 188 466 371 788 8 × 2 = 1 + 0.169 290 983 503 742 609 173 059 463 500 976 560 806 376 932 743 577 6;
  • 54) 0.169 290 983 503 742 609 173 059 463 500 976 560 806 376 932 743 577 6 × 2 = 0 + 0.338 581 967 007 485 218 346 118 927 001 953 121 612 753 865 487 155 2;
  • 55) 0.338 581 967 007 485 218 346 118 927 001 953 121 612 753 865 487 155 2 × 2 = 0 + 0.677 163 934 014 970 436 692 237 854 003 906 243 225 507 730 974 310 4;
  • 56) 0.677 163 934 014 970 436 692 237 854 003 906 243 225 507 730 974 310 4 × 2 = 1 + 0.354 327 868 029 940 873 384 475 708 007 812 486 451 015 461 948 620 8;
  • 57) 0.354 327 868 029 940 873 384 475 708 007 812 486 451 015 461 948 620 8 × 2 = 0 + 0.708 655 736 059 881 746 768 951 416 015 624 972 902 030 923 897 241 6;
  • 58) 0.708 655 736 059 881 746 768 951 416 015 624 972 902 030 923 897 241 6 × 2 = 1 + 0.417 311 472 119 763 493 537 902 832 031 249 945 804 061 847 794 483 2;
  • 59) 0.417 311 472 119 763 493 537 902 832 031 249 945 804 061 847 794 483 2 × 2 = 0 + 0.834 622 944 239 526 987 075 805 664 062 499 891 608 123 695 588 966 4;
  • 60) 0.834 622 944 239 526 987 075 805 664 062 499 891 608 123 695 588 966 4 × 2 = 1 + 0.669 245 888 479 053 974 151 611 328 124 999 783 216 247 391 177 932 8;
  • 61) 0.669 245 888 479 053 974 151 611 328 124 999 783 216 247 391 177 932 8 × 2 = 1 + 0.338 491 776 958 107 948 303 222 656 249 999 566 432 494 782 355 865 6;
  • 62) 0.338 491 776 958 107 948 303 222 656 249 999 566 432 494 782 355 865 6 × 2 = 0 + 0.676 983 553 916 215 896 606 445 312 499 999 132 864 989 564 711 731 2;
  • 63) 0.676 983 553 916 215 896 606 445 312 499 999 132 864 989 564 711 731 2 × 2 = 1 + 0.353 967 107 832 431 793 212 890 624 999 998 265 729 979 129 423 462 4;
  • 64) 0.353 967 107 832 431 793 212 890 624 999 998 265 729 979 129 423 462 4 × 2 = 0 + 0.707 934 215 664 863 586 425 781 249 999 996 531 459 958 258 846 924 8;
  • 65) 0.707 934 215 664 863 586 425 781 249 999 996 531 459 958 258 846 924 8 × 2 = 1 + 0.415 868 431 329 727 172 851 562 499 999 993 062 919 916 517 693 849 6;
  • 66) 0.415 868 431 329 727 172 851 562 499 999 993 062 919 916 517 693 849 6 × 2 = 0 + 0.831 736 862 659 454 345 703 124 999 999 986 125 839 833 035 387 699 2;
  • 67) 0.831 736 862 659 454 345 703 124 999 999 986 125 839 833 035 387 699 2 × 2 = 1 + 0.663 473 725 318 908 691 406 249 999 999 972 251 679 666 070 775 398 4;
  • 68) 0.663 473 725 318 908 691 406 249 999 999 972 251 679 666 070 775 398 4 × 2 = 1 + 0.326 947 450 637 817 382 812 499 999 999 944 503 359 332 141 550 796 8;
  • 69) 0.326 947 450 637 817 382 812 499 999 999 944 503 359 332 141 550 796 8 × 2 = 0 + 0.653 894 901 275 634 765 624 999 999 999 889 006 718 664 283 101 593 6;
  • 70) 0.653 894 901 275 634 765 624 999 999 999 889 006 718 664 283 101 593 6 × 2 = 1 + 0.307 789 802 551 269 531 249 999 999 999 778 013 437 328 566 203 187 2;
  • 71) 0.307 789 802 551 269 531 249 999 999 999 778 013 437 328 566 203 187 2 × 2 = 0 + 0.615 579 605 102 539 062 499 999 999 999 556 026 874 657 132 406 374 4;
  • 72) 0.615 579 605 102 539 062 499 999 999 999 556 026 874 657 132 406 374 4 × 2 = 1 + 0.231 159 210 205 078 124 999 999 999 999 112 053 749 314 264 812 748 8;
  • 73) 0.231 159 210 205 078 124 999 999 999 999 112 053 749 314 264 812 748 8 × 2 = 0 + 0.462 318 420 410 156 249 999 999 999 998 224 107 498 628 529 625 497 6;
  • 74) 0.462 318 420 410 156 249 999 999 999 998 224 107 498 628 529 625 497 6 × 2 = 0 + 0.924 636 840 820 312 499 999 999 999 996 448 214 997 257 059 250 995 2;
  • 75) 0.924 636 840 820 312 499 999 999 999 996 448 214 997 257 059 250 995 2 × 2 = 1 + 0.849 273 681 640 624 999 999 999 999 992 896 429 994 514 118 501 990 4;
  • 76) 0.849 273 681 640 624 999 999 999 999 992 896 429 994 514 118 501 990 4 × 2 = 1 + 0.698 547 363 281 249 999 999 999 999 985 792 859 989 028 237 003 980 8;
  • 77) 0.698 547 363 281 249 999 999 999 999 985 792 859 989 028 237 003 980 8 × 2 = 1 + 0.397 094 726 562 499 999 999 999 999 971 585 719 978 056 474 007 961 6;
  • 78) 0.397 094 726 562 499 999 999 999 999 971 585 719 978 056 474 007 961 6 × 2 = 0 + 0.794 189 453 124 999 999 999 999 999 943 171 439 956 112 948 015 923 2;
  • 79) 0.794 189 453 124 999 999 999 999 999 943 171 439 956 112 948 015 923 2 × 2 = 1 + 0.588 378 906 249 999 999 999 999 999 886 342 879 912 225 896 031 846 4;
  • 80) 0.588 378 906 249 999 999 999 999 999 886 342 879 912 225 896 031 846 4 × 2 = 1 + 0.176 757 812 499 999 999 999 999 999 772 685 759 824 451 792 063 692 8;
  • 81) 0.176 757 812 499 999 999 999 999 999 772 685 759 824 451 792 063 692 8 × 2 = 0 + 0.353 515 624 999 999 999 999 999 999 545 371 519 648 903 584 127 385 6;
  • 82) 0.353 515 624 999 999 999 999 999 999 545 371 519 648 903 584 127 385 6 × 2 = 0 + 0.707 031 249 999 999 999 999 999 999 090 743 039 297 807 168 254 771 2;
  • 83) 0.707 031 249 999 999 999 999 999 999 090 743 039 297 807 168 254 771 2 × 2 = 1 + 0.414 062 499 999 999 999 999 999 998 181 486 078 595 614 336 509 542 4;
  • 84) 0.414 062 499 999 999 999 999 999 998 181 486 078 595 614 336 509 542 4 × 2 = 0 + 0.828 124 999 999 999 999 999 999 996 362 972 157 191 228 673 019 084 8;
  • 85) 0.828 124 999 999 999 999 999 999 996 362 972 157 191 228 673 019 084 8 × 2 = 1 + 0.656 249 999 999 999 999 999 999 992 725 944 314 382 457 346 038 169 6;
  • 86) 0.656 249 999 999 999 999 999 999 992 725 944 314 382 457 346 038 169 6 × 2 = 1 + 0.312 499 999 999 999 999 999 999 985 451 888 628 764 914 692 076 339 2;
  • 87) 0.312 499 999 999 999 999 999 999 985 451 888 628 764 914 692 076 339 2 × 2 = 0 + 0.624 999 999 999 999 999 999 999 970 903 777 257 529 829 384 152 678 4;
  • 88) 0.624 999 999 999 999 999 999 999 970 903 777 257 529 829 384 152 678 4 × 2 = 1 + 0.249 999 999 999 999 999 999 999 941 807 554 515 059 658 768 305 356 8;
  • 89) 0.249 999 999 999 999 999 999 999 941 807 554 515 059 658 768 305 356 8 × 2 = 0 + 0.499 999 999 999 999 999 999 999 883 615 109 030 119 317 536 610 713 6;
  • 90) 0.499 999 999 999 999 999 999 999 883 615 109 030 119 317 536 610 713 6 × 2 = 0 + 0.999 999 999 999 999 999 999 999 767 230 218 060 238 635 073 221 427 2;
  • 91) 0.999 999 999 999 999 999 999 999 767 230 218 060 238 635 073 221 427 2 × 2 = 1 + 0.999 999 999 999 999 999 999 999 534 460 436 120 477 270 146 442 854 4;

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:


0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 001(2)

5. Positive number before normalization:

0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 001(2)

6. Normalize the binary representation of the number.

Shift the decimal mark 39 positions to the right, so that only one non zero digit remains to the left of it:


0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8(10) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 001(2) =


0.0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111 0010 1001 0101 1010 1011 0101 0011 1011 0010 1101 001(2) × 20 =


1.1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001(2) × 2-39


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): -39


Mantissa (not normalized):
1.1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001


8. Adjust the exponent.

Use the 11 bit excess/bias notation:


Exponent (adjusted) =


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


-39 + 2(11-1) - 1 =


(-39 + 1 023)(10) =


984(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;
  • 984 ÷ 2 = 492 + 0;
  • 492 ÷ 2 = 246 + 0;
  • 246 ÷ 2 = 123 + 0;
  • 123 ÷ 2 = 61 + 1;
  • 61 ÷ 2 = 30 + 1;
  • 30 ÷ 2 = 15 + 0;
  • 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) =


984(10) =


011 1101 1000(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. 1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001 =


1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001


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 1101 1000


Mantissa (52 bits) =
1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001


Decimal number 0.000 000 000 003 634 999 999 999 999 758 261 057 032 300 678 335 152 8 converted to 64 bit double precision IEEE 754 binary floating point representation:

0 - 011 1101 1000 - 1111 1111 1001 0100 1010 1101 0101 1010 1001 1101 1001 0110 1001


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