0.000 020 830 729 321 671 205 134 999 154 509 660 617 05 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 020 830 729 321 671 205 134 999 154 509 660 617 05(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
0.000 020 830 729 321 671 205 134 999 154 509 660 617 05(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: 0.000 020 830 729 321 671 205 134 999 154 509 660 617 05.

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) 0.000 020 830 729 321 671 205 134 999 154 509 660 617 05 × 2 = 0 + 0.000 041 661 458 643 342 410 269 998 309 019 321 234 1;
  • 2) 0.000 041 661 458 643 342 410 269 998 309 019 321 234 1 × 2 = 0 + 0.000 083 322 917 286 684 820 539 996 618 038 642 468 2;
  • 3) 0.000 083 322 917 286 684 820 539 996 618 038 642 468 2 × 2 = 0 + 0.000 166 645 834 573 369 641 079 993 236 077 284 936 4;
  • 4) 0.000 166 645 834 573 369 641 079 993 236 077 284 936 4 × 2 = 0 + 0.000 333 291 669 146 739 282 159 986 472 154 569 872 8;
  • 5) 0.000 333 291 669 146 739 282 159 986 472 154 569 872 8 × 2 = 0 + 0.000 666 583 338 293 478 564 319 972 944 309 139 745 6;
  • 6) 0.000 666 583 338 293 478 564 319 972 944 309 139 745 6 × 2 = 0 + 0.001 333 166 676 586 957 128 639 945 888 618 279 491 2;
  • 7) 0.001 333 166 676 586 957 128 639 945 888 618 279 491 2 × 2 = 0 + 0.002 666 333 353 173 914 257 279 891 777 236 558 982 4;
  • 8) 0.002 666 333 353 173 914 257 279 891 777 236 558 982 4 × 2 = 0 + 0.005 332 666 706 347 828 514 559 783 554 473 117 964 8;
  • 9) 0.005 332 666 706 347 828 514 559 783 554 473 117 964 8 × 2 = 0 + 0.010 665 333 412 695 657 029 119 567 108 946 235 929 6;
  • 10) 0.010 665 333 412 695 657 029 119 567 108 946 235 929 6 × 2 = 0 + 0.021 330 666 825 391 314 058 239 134 217 892 471 859 2;
  • 11) 0.021 330 666 825 391 314 058 239 134 217 892 471 859 2 × 2 = 0 + 0.042 661 333 650 782 628 116 478 268 435 784 943 718 4;
  • 12) 0.042 661 333 650 782 628 116 478 268 435 784 943 718 4 × 2 = 0 + 0.085 322 667 301 565 256 232 956 536 871 569 887 436 8;
  • 13) 0.085 322 667 301 565 256 232 956 536 871 569 887 436 8 × 2 = 0 + 0.170 645 334 603 130 512 465 913 073 743 139 774 873 6;
  • 14) 0.170 645 334 603 130 512 465 913 073 743 139 774 873 6 × 2 = 0 + 0.341 290 669 206 261 024 931 826 147 486 279 549 747 2;
  • 15) 0.341 290 669 206 261 024 931 826 147 486 279 549 747 2 × 2 = 0 + 0.682 581 338 412 522 049 863 652 294 972 559 099 494 4;
  • 16) 0.682 581 338 412 522 049 863 652 294 972 559 099 494 4 × 2 = 1 + 0.365 162 676 825 044 099 727 304 589 945 118 198 988 8;
  • 17) 0.365 162 676 825 044 099 727 304 589 945 118 198 988 8 × 2 = 0 + 0.730 325 353 650 088 199 454 609 179 890 236 397 977 6;
  • 18) 0.730 325 353 650 088 199 454 609 179 890 236 397 977 6 × 2 = 1 + 0.460 650 707 300 176 398 909 218 359 780 472 795 955 2;
  • 19) 0.460 650 707 300 176 398 909 218 359 780 472 795 955 2 × 2 = 0 + 0.921 301 414 600 352 797 818 436 719 560 945 591 910 4;
  • 20) 0.921 301 414 600 352 797 818 436 719 560 945 591 910 4 × 2 = 1 + 0.842 602 829 200 705 595 636 873 439 121 891 183 820 8;
  • 21) 0.842 602 829 200 705 595 636 873 439 121 891 183 820 8 × 2 = 1 + 0.685 205 658 401 411 191 273 746 878 243 782 367 641 6;
  • 22) 0.685 205 658 401 411 191 273 746 878 243 782 367 641 6 × 2 = 1 + 0.370 411 316 802 822 382 547 493 756 487 564 735 283 2;
  • 23) 0.370 411 316 802 822 382 547 493 756 487 564 735 283 2 × 2 = 0 + 0.740 822 633 605 644 765 094 987 512 975 129 470 566 4;
  • 24) 0.740 822 633 605 644 765 094 987 512 975 129 470 566 4 × 2 = 1 + 0.481 645 267 211 289 530 189 975 025 950 258 941 132 8;
  • 25) 0.481 645 267 211 289 530 189 975 025 950 258 941 132 8 × 2 = 0 + 0.963 290 534 422 579 060 379 950 051 900 517 882 265 6;
  • 26) 0.963 290 534 422 579 060 379 950 051 900 517 882 265 6 × 2 = 1 + 0.926 581 068 845 158 120 759 900 103 801 035 764 531 2;
  • 27) 0.926 581 068 845 158 120 759 900 103 801 035 764 531 2 × 2 = 1 + 0.853 162 137 690 316 241 519 800 207 602 071 529 062 4;
  • 28) 0.853 162 137 690 316 241 519 800 207 602 071 529 062 4 × 2 = 1 + 0.706 324 275 380 632 483 039 600 415 204 143 058 124 8;
  • 29) 0.706 324 275 380 632 483 039 600 415 204 143 058 124 8 × 2 = 1 + 0.412 648 550 761 264 966 079 200 830 408 286 116 249 6;
  • 30) 0.412 648 550 761 264 966 079 200 830 408 286 116 249 6 × 2 = 0 + 0.825 297 101 522 529 932 158 401 660 816 572 232 499 2;
  • 31) 0.825 297 101 522 529 932 158 401 660 816 572 232 499 2 × 2 = 1 + 0.650 594 203 045 059 864 316 803 321 633 144 464 998 4;
  • 32) 0.650 594 203 045 059 864 316 803 321 633 144 464 998 4 × 2 = 1 + 0.301 188 406 090 119 728 633 606 643 266 288 929 996 8;
  • 33) 0.301 188 406 090 119 728 633 606 643 266 288 929 996 8 × 2 = 0 + 0.602 376 812 180 239 457 267 213 286 532 577 859 993 6;
  • 34) 0.602 376 812 180 239 457 267 213 286 532 577 859 993 6 × 2 = 1 + 0.204 753 624 360 478 914 534 426 573 065 155 719 987 2;
  • 35) 0.204 753 624 360 478 914 534 426 573 065 155 719 987 2 × 2 = 0 + 0.409 507 248 720 957 829 068 853 146 130 311 439 974 4;
  • 36) 0.409 507 248 720 957 829 068 853 146 130 311 439 974 4 × 2 = 0 + 0.819 014 497 441 915 658 137 706 292 260 622 879 948 8;
  • 37) 0.819 014 497 441 915 658 137 706 292 260 622 879 948 8 × 2 = 1 + 0.638 028 994 883 831 316 275 412 584 521 245 759 897 6;
  • 38) 0.638 028 994 883 831 316 275 412 584 521 245 759 897 6 × 2 = 1 + 0.276 057 989 767 662 632 550 825 169 042 491 519 795 2;
  • 39) 0.276 057 989 767 662 632 550 825 169 042 491 519 795 2 × 2 = 0 + 0.552 115 979 535 325 265 101 650 338 084 983 039 590 4;
  • 40) 0.552 115 979 535 325 265 101 650 338 084 983 039 590 4 × 2 = 1 + 0.104 231 959 070 650 530 203 300 676 169 966 079 180 8;
  • 41) 0.104 231 959 070 650 530 203 300 676 169 966 079 180 8 × 2 = 0 + 0.208 463 918 141 301 060 406 601 352 339 932 158 361 6;
  • 42) 0.208 463 918 141 301 060 406 601 352 339 932 158 361 6 × 2 = 0 + 0.416 927 836 282 602 120 813 202 704 679 864 316 723 2;
  • 43) 0.416 927 836 282 602 120 813 202 704 679 864 316 723 2 × 2 = 0 + 0.833 855 672 565 204 241 626 405 409 359 728 633 446 4;
  • 44) 0.833 855 672 565 204 241 626 405 409 359 728 633 446 4 × 2 = 1 + 0.667 711 345 130 408 483 252 810 818 719 457 266 892 8;
  • 45) 0.667 711 345 130 408 483 252 810 818 719 457 266 892 8 × 2 = 1 + 0.335 422 690 260 816 966 505 621 637 438 914 533 785 6;
  • 46) 0.335 422 690 260 816 966 505 621 637 438 914 533 785 6 × 2 = 0 + 0.670 845 380 521 633 933 011 243 274 877 829 067 571 2;
  • 47) 0.670 845 380 521 633 933 011 243 274 877 829 067 571 2 × 2 = 1 + 0.341 690 761 043 267 866 022 486 549 755 658 135 142 4;
  • 48) 0.341 690 761 043 267 866 022 486 549 755 658 135 142 4 × 2 = 0 + 0.683 381 522 086 535 732 044 973 099 511 316 270 284 8;
  • 49) 0.683 381 522 086 535 732 044 973 099 511 316 270 284 8 × 2 = 1 + 0.366 763 044 173 071 464 089 946 199 022 632 540 569 6;
  • 50) 0.366 763 044 173 071 464 089 946 199 022 632 540 569 6 × 2 = 0 + 0.733 526 088 346 142 928 179 892 398 045 265 081 139 2;
  • 51) 0.733 526 088 346 142 928 179 892 398 045 265 081 139 2 × 2 = 1 + 0.467 052 176 692 285 856 359 784 796 090 530 162 278 4;
  • 52) 0.467 052 176 692 285 856 359 784 796 090 530 162 278 4 × 2 = 0 + 0.934 104 353 384 571 712 719 569 592 181 060 324 556 8;
  • 53) 0.934 104 353 384 571 712 719 569 592 181 060 324 556 8 × 2 = 1 + 0.868 208 706 769 143 425 439 139 184 362 120 649 113 6;
  • 54) 0.868 208 706 769 143 425 439 139 184 362 120 649 113 6 × 2 = 1 + 0.736 417 413 538 286 850 878 278 368 724 241 298 227 2;
  • 55) 0.736 417 413 538 286 850 878 278 368 724 241 298 227 2 × 2 = 1 + 0.472 834 827 076 573 701 756 556 737 448 482 596 454 4;
  • 56) 0.472 834 827 076 573 701 756 556 737 448 482 596 454 4 × 2 = 0 + 0.945 669 654 153 147 403 513 113 474 896 965 192 908 8;
  • 57) 0.945 669 654 153 147 403 513 113 474 896 965 192 908 8 × 2 = 1 + 0.891 339 308 306 294 807 026 226 949 793 930 385 817 6;
  • 58) 0.891 339 308 306 294 807 026 226 949 793 930 385 817 6 × 2 = 1 + 0.782 678 616 612 589 614 052 453 899 587 860 771 635 2;
  • 59) 0.782 678 616 612 589 614 052 453 899 587 860 771 635 2 × 2 = 1 + 0.565 357 233 225 179 228 104 907 799 175 721 543 270 4;
  • 60) 0.565 357 233 225 179 228 104 907 799 175 721 543 270 4 × 2 = 1 + 0.130 714 466 450 358 456 209 815 598 351 443 086 540 8;
  • 61) 0.130 714 466 450 358 456 209 815 598 351 443 086 540 8 × 2 = 0 + 0.261 428 932 900 716 912 419 631 196 702 886 173 081 6;
  • 62) 0.261 428 932 900 716 912 419 631 196 702 886 173 081 6 × 2 = 0 + 0.522 857 865 801 433 824 839 262 393 405 772 346 163 2;
  • 63) 0.522 857 865 801 433 824 839 262 393 405 772 346 163 2 × 2 = 1 + 0.045 715 731 602 867 649 678 524 786 811 544 692 326 4;
  • 64) 0.045 715 731 602 867 649 678 524 786 811 544 692 326 4 × 2 = 0 + 0.091 431 463 205 735 299 357 049 573 623 089 384 652 8;
  • 65) 0.091 431 463 205 735 299 357 049 573 623 089 384 652 8 × 2 = 0 + 0.182 862 926 411 470 598 714 099 147 246 178 769 305 6;
  • 66) 0.182 862 926 411 470 598 714 099 147 246 178 769 305 6 × 2 = 0 + 0.365 725 852 822 941 197 428 198 294 492 357 538 611 2;
  • 67) 0.365 725 852 822 941 197 428 198 294 492 357 538 611 2 × 2 = 0 + 0.731 451 705 645 882 394 856 396 588 984 715 077 222 4;
  • 68) 0.731 451 705 645 882 394 856 396 588 984 715 077 222 4 × 2 = 1 + 0.462 903 411 291 764 789 712 793 177 969 430 154 444 8;

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:


0.000 020 830 729 321 671 205 134 999 154 509 660 617 05(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:

0.000 020 830 729 321 671 205 134 999 154 509 660 617 05(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:


0.000 020 830 729 321 671 205 134 999 154 509 660 617 05(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 0.000 020 830 729 321 671 205 134 999 154 509 660 617 05 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