0.000 020 830 729 321 671 205 134 999 154 509 660 618 129 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 020 830 729 321 671 205 134 999 154 509 660 618 129(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
0.000 020 830 729 321 671 205 134 999 154 509 660 618 129(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: 0.000 020 830 729 321 671 205 134 999 154 509 660 618 129.

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) 0.000 020 830 729 321 671 205 134 999 154 509 660 618 129 × 2 = 0 + 0.000 041 661 458 643 342 410 269 998 309 019 321 236 258;
  • 2) 0.000 041 661 458 643 342 410 269 998 309 019 321 236 258 × 2 = 0 + 0.000 083 322 917 286 684 820 539 996 618 038 642 472 516;
  • 3) 0.000 083 322 917 286 684 820 539 996 618 038 642 472 516 × 2 = 0 + 0.000 166 645 834 573 369 641 079 993 236 077 284 945 032;
  • 4) 0.000 166 645 834 573 369 641 079 993 236 077 284 945 032 × 2 = 0 + 0.000 333 291 669 146 739 282 159 986 472 154 569 890 064;
  • 5) 0.000 333 291 669 146 739 282 159 986 472 154 569 890 064 × 2 = 0 + 0.000 666 583 338 293 478 564 319 972 944 309 139 780 128;
  • 6) 0.000 666 583 338 293 478 564 319 972 944 309 139 780 128 × 2 = 0 + 0.001 333 166 676 586 957 128 639 945 888 618 279 560 256;
  • 7) 0.001 333 166 676 586 957 128 639 945 888 618 279 560 256 × 2 = 0 + 0.002 666 333 353 173 914 257 279 891 777 236 559 120 512;
  • 8) 0.002 666 333 353 173 914 257 279 891 777 236 559 120 512 × 2 = 0 + 0.005 332 666 706 347 828 514 559 783 554 473 118 241 024;
  • 9) 0.005 332 666 706 347 828 514 559 783 554 473 118 241 024 × 2 = 0 + 0.010 665 333 412 695 657 029 119 567 108 946 236 482 048;
  • 10) 0.010 665 333 412 695 657 029 119 567 108 946 236 482 048 × 2 = 0 + 0.021 330 666 825 391 314 058 239 134 217 892 472 964 096;
  • 11) 0.021 330 666 825 391 314 058 239 134 217 892 472 964 096 × 2 = 0 + 0.042 661 333 650 782 628 116 478 268 435 784 945 928 192;
  • 12) 0.042 661 333 650 782 628 116 478 268 435 784 945 928 192 × 2 = 0 + 0.085 322 667 301 565 256 232 956 536 871 569 891 856 384;
  • 13) 0.085 322 667 301 565 256 232 956 536 871 569 891 856 384 × 2 = 0 + 0.170 645 334 603 130 512 465 913 073 743 139 783 712 768;
  • 14) 0.170 645 334 603 130 512 465 913 073 743 139 783 712 768 × 2 = 0 + 0.341 290 669 206 261 024 931 826 147 486 279 567 425 536;
  • 15) 0.341 290 669 206 261 024 931 826 147 486 279 567 425 536 × 2 = 0 + 0.682 581 338 412 522 049 863 652 294 972 559 134 851 072;
  • 16) 0.682 581 338 412 522 049 863 652 294 972 559 134 851 072 × 2 = 1 + 0.365 162 676 825 044 099 727 304 589 945 118 269 702 144;
  • 17) 0.365 162 676 825 044 099 727 304 589 945 118 269 702 144 × 2 = 0 + 0.730 325 353 650 088 199 454 609 179 890 236 539 404 288;
  • 18) 0.730 325 353 650 088 199 454 609 179 890 236 539 404 288 × 2 = 1 + 0.460 650 707 300 176 398 909 218 359 780 473 078 808 576;
  • 19) 0.460 650 707 300 176 398 909 218 359 780 473 078 808 576 × 2 = 0 + 0.921 301 414 600 352 797 818 436 719 560 946 157 617 152;
  • 20) 0.921 301 414 600 352 797 818 436 719 560 946 157 617 152 × 2 = 1 + 0.842 602 829 200 705 595 636 873 439 121 892 315 234 304;
  • 21) 0.842 602 829 200 705 595 636 873 439 121 892 315 234 304 × 2 = 1 + 0.685 205 658 401 411 191 273 746 878 243 784 630 468 608;
  • 22) 0.685 205 658 401 411 191 273 746 878 243 784 630 468 608 × 2 = 1 + 0.370 411 316 802 822 382 547 493 756 487 569 260 937 216;
  • 23) 0.370 411 316 802 822 382 547 493 756 487 569 260 937 216 × 2 = 0 + 0.740 822 633 605 644 765 094 987 512 975 138 521 874 432;
  • 24) 0.740 822 633 605 644 765 094 987 512 975 138 521 874 432 × 2 = 1 + 0.481 645 267 211 289 530 189 975 025 950 277 043 748 864;
  • 25) 0.481 645 267 211 289 530 189 975 025 950 277 043 748 864 × 2 = 0 + 0.963 290 534 422 579 060 379 950 051 900 554 087 497 728;
  • 26) 0.963 290 534 422 579 060 379 950 051 900 554 087 497 728 × 2 = 1 + 0.926 581 068 845 158 120 759 900 103 801 108 174 995 456;
  • 27) 0.926 581 068 845 158 120 759 900 103 801 108 174 995 456 × 2 = 1 + 0.853 162 137 690 316 241 519 800 207 602 216 349 990 912;
  • 28) 0.853 162 137 690 316 241 519 800 207 602 216 349 990 912 × 2 = 1 + 0.706 324 275 380 632 483 039 600 415 204 432 699 981 824;
  • 29) 0.706 324 275 380 632 483 039 600 415 204 432 699 981 824 × 2 = 1 + 0.412 648 550 761 264 966 079 200 830 408 865 399 963 648;
  • 30) 0.412 648 550 761 264 966 079 200 830 408 865 399 963 648 × 2 = 0 + 0.825 297 101 522 529 932 158 401 660 817 730 799 927 296;
  • 31) 0.825 297 101 522 529 932 158 401 660 817 730 799 927 296 × 2 = 1 + 0.650 594 203 045 059 864 316 803 321 635 461 599 854 592;
  • 32) 0.650 594 203 045 059 864 316 803 321 635 461 599 854 592 × 2 = 1 + 0.301 188 406 090 119 728 633 606 643 270 923 199 709 184;
  • 33) 0.301 188 406 090 119 728 633 606 643 270 923 199 709 184 × 2 = 0 + 0.602 376 812 180 239 457 267 213 286 541 846 399 418 368;
  • 34) 0.602 376 812 180 239 457 267 213 286 541 846 399 418 368 × 2 = 1 + 0.204 753 624 360 478 914 534 426 573 083 692 798 836 736;
  • 35) 0.204 753 624 360 478 914 534 426 573 083 692 798 836 736 × 2 = 0 + 0.409 507 248 720 957 829 068 853 146 167 385 597 673 472;
  • 36) 0.409 507 248 720 957 829 068 853 146 167 385 597 673 472 × 2 = 0 + 0.819 014 497 441 915 658 137 706 292 334 771 195 346 944;
  • 37) 0.819 014 497 441 915 658 137 706 292 334 771 195 346 944 × 2 = 1 + 0.638 028 994 883 831 316 275 412 584 669 542 390 693 888;
  • 38) 0.638 028 994 883 831 316 275 412 584 669 542 390 693 888 × 2 = 1 + 0.276 057 989 767 662 632 550 825 169 339 084 781 387 776;
  • 39) 0.276 057 989 767 662 632 550 825 169 339 084 781 387 776 × 2 = 0 + 0.552 115 979 535 325 265 101 650 338 678 169 562 775 552;
  • 40) 0.552 115 979 535 325 265 101 650 338 678 169 562 775 552 × 2 = 1 + 0.104 231 959 070 650 530 203 300 677 356 339 125 551 104;
  • 41) 0.104 231 959 070 650 530 203 300 677 356 339 125 551 104 × 2 = 0 + 0.208 463 918 141 301 060 406 601 354 712 678 251 102 208;
  • 42) 0.208 463 918 141 301 060 406 601 354 712 678 251 102 208 × 2 = 0 + 0.416 927 836 282 602 120 813 202 709 425 356 502 204 416;
  • 43) 0.416 927 836 282 602 120 813 202 709 425 356 502 204 416 × 2 = 0 + 0.833 855 672 565 204 241 626 405 418 850 713 004 408 832;
  • 44) 0.833 855 672 565 204 241 626 405 418 850 713 004 408 832 × 2 = 1 + 0.667 711 345 130 408 483 252 810 837 701 426 008 817 664;
  • 45) 0.667 711 345 130 408 483 252 810 837 701 426 008 817 664 × 2 = 1 + 0.335 422 690 260 816 966 505 621 675 402 852 017 635 328;
  • 46) 0.335 422 690 260 816 966 505 621 675 402 852 017 635 328 × 2 = 0 + 0.670 845 380 521 633 933 011 243 350 805 704 035 270 656;
  • 47) 0.670 845 380 521 633 933 011 243 350 805 704 035 270 656 × 2 = 1 + 0.341 690 761 043 267 866 022 486 701 611 408 070 541 312;
  • 48) 0.341 690 761 043 267 866 022 486 701 611 408 070 541 312 × 2 = 0 + 0.683 381 522 086 535 732 044 973 403 222 816 141 082 624;
  • 49) 0.683 381 522 086 535 732 044 973 403 222 816 141 082 624 × 2 = 1 + 0.366 763 044 173 071 464 089 946 806 445 632 282 165 248;
  • 50) 0.366 763 044 173 071 464 089 946 806 445 632 282 165 248 × 2 = 0 + 0.733 526 088 346 142 928 179 893 612 891 264 564 330 496;
  • 51) 0.733 526 088 346 142 928 179 893 612 891 264 564 330 496 × 2 = 1 + 0.467 052 176 692 285 856 359 787 225 782 529 128 660 992;
  • 52) 0.467 052 176 692 285 856 359 787 225 782 529 128 660 992 × 2 = 0 + 0.934 104 353 384 571 712 719 574 451 565 058 257 321 984;
  • 53) 0.934 104 353 384 571 712 719 574 451 565 058 257 321 984 × 2 = 1 + 0.868 208 706 769 143 425 439 148 903 130 116 514 643 968;
  • 54) 0.868 208 706 769 143 425 439 148 903 130 116 514 643 968 × 2 = 1 + 0.736 417 413 538 286 850 878 297 806 260 233 029 287 936;
  • 55) 0.736 417 413 538 286 850 878 297 806 260 233 029 287 936 × 2 = 1 + 0.472 834 827 076 573 701 756 595 612 520 466 058 575 872;
  • 56) 0.472 834 827 076 573 701 756 595 612 520 466 058 575 872 × 2 = 0 + 0.945 669 654 153 147 403 513 191 225 040 932 117 151 744;
  • 57) 0.945 669 654 153 147 403 513 191 225 040 932 117 151 744 × 2 = 1 + 0.891 339 308 306 294 807 026 382 450 081 864 234 303 488;
  • 58) 0.891 339 308 306 294 807 026 382 450 081 864 234 303 488 × 2 = 1 + 0.782 678 616 612 589 614 052 764 900 163 728 468 606 976;
  • 59) 0.782 678 616 612 589 614 052 764 900 163 728 468 606 976 × 2 = 1 + 0.565 357 233 225 179 228 105 529 800 327 456 937 213 952;
  • 60) 0.565 357 233 225 179 228 105 529 800 327 456 937 213 952 × 2 = 1 + 0.130 714 466 450 358 456 211 059 600 654 913 874 427 904;
  • 61) 0.130 714 466 450 358 456 211 059 600 654 913 874 427 904 × 2 = 0 + 0.261 428 932 900 716 912 422 119 201 309 827 748 855 808;
  • 62) 0.261 428 932 900 716 912 422 119 201 309 827 748 855 808 × 2 = 0 + 0.522 857 865 801 433 824 844 238 402 619 655 497 711 616;
  • 63) 0.522 857 865 801 433 824 844 238 402 619 655 497 711 616 × 2 = 1 + 0.045 715 731 602 867 649 688 476 805 239 310 995 423 232;
  • 64) 0.045 715 731 602 867 649 688 476 805 239 310 995 423 232 × 2 = 0 + 0.091 431 463 205 735 299 376 953 610 478 621 990 846 464;
  • 65) 0.091 431 463 205 735 299 376 953 610 478 621 990 846 464 × 2 = 0 + 0.182 862 926 411 470 598 753 907 220 957 243 981 692 928;
  • 66) 0.182 862 926 411 470 598 753 907 220 957 243 981 692 928 × 2 = 0 + 0.365 725 852 822 941 197 507 814 441 914 487 963 385 856;
  • 67) 0.365 725 852 822 941 197 507 814 441 914 487 963 385 856 × 2 = 0 + 0.731 451 705 645 882 395 015 628 883 828 975 926 771 712;
  • 68) 0.731 451 705 645 882 395 015 628 883 828 975 926 771 712 × 2 = 1 + 0.462 903 411 291 764 790 031 257 767 657 951 853 543 424;

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:


0.000 020 830 729 321 671 205 134 999 154 509 660 618 129(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:

0.000 020 830 729 321 671 205 134 999 154 509 660 618 129(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:


0.000 020 830 729 321 671 205 134 999 154 509 660 618 129(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 0.000 020 830 729 321 671 205 134 999 154 509 660 618 129 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