0.000 020 830 729 321 671 205 134 999 154 509 660 651 9 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 020 830 729 321 671 205 134 999 154 509 660 651 9(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
0.000 020 830 729 321 671 205 134 999 154 509 660 651 9(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: 0.000 020 830 729 321 671 205 134 999 154 509 660 651 9.

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) 0.000 020 830 729 321 671 205 134 999 154 509 660 651 9 × 2 = 0 + 0.000 041 661 458 643 342 410 269 998 309 019 321 303 8;
  • 2) 0.000 041 661 458 643 342 410 269 998 309 019 321 303 8 × 2 = 0 + 0.000 083 322 917 286 684 820 539 996 618 038 642 607 6;
  • 3) 0.000 083 322 917 286 684 820 539 996 618 038 642 607 6 × 2 = 0 + 0.000 166 645 834 573 369 641 079 993 236 077 285 215 2;
  • 4) 0.000 166 645 834 573 369 641 079 993 236 077 285 215 2 × 2 = 0 + 0.000 333 291 669 146 739 282 159 986 472 154 570 430 4;
  • 5) 0.000 333 291 669 146 739 282 159 986 472 154 570 430 4 × 2 = 0 + 0.000 666 583 338 293 478 564 319 972 944 309 140 860 8;
  • 6) 0.000 666 583 338 293 478 564 319 972 944 309 140 860 8 × 2 = 0 + 0.001 333 166 676 586 957 128 639 945 888 618 281 721 6;
  • 7) 0.001 333 166 676 586 957 128 639 945 888 618 281 721 6 × 2 = 0 + 0.002 666 333 353 173 914 257 279 891 777 236 563 443 2;
  • 8) 0.002 666 333 353 173 914 257 279 891 777 236 563 443 2 × 2 = 0 + 0.005 332 666 706 347 828 514 559 783 554 473 126 886 4;
  • 9) 0.005 332 666 706 347 828 514 559 783 554 473 126 886 4 × 2 = 0 + 0.010 665 333 412 695 657 029 119 567 108 946 253 772 8;
  • 10) 0.010 665 333 412 695 657 029 119 567 108 946 253 772 8 × 2 = 0 + 0.021 330 666 825 391 314 058 239 134 217 892 507 545 6;
  • 11) 0.021 330 666 825 391 314 058 239 134 217 892 507 545 6 × 2 = 0 + 0.042 661 333 650 782 628 116 478 268 435 785 015 091 2;
  • 12) 0.042 661 333 650 782 628 116 478 268 435 785 015 091 2 × 2 = 0 + 0.085 322 667 301 565 256 232 956 536 871 570 030 182 4;
  • 13) 0.085 322 667 301 565 256 232 956 536 871 570 030 182 4 × 2 = 0 + 0.170 645 334 603 130 512 465 913 073 743 140 060 364 8;
  • 14) 0.170 645 334 603 130 512 465 913 073 743 140 060 364 8 × 2 = 0 + 0.341 290 669 206 261 024 931 826 147 486 280 120 729 6;
  • 15) 0.341 290 669 206 261 024 931 826 147 486 280 120 729 6 × 2 = 0 + 0.682 581 338 412 522 049 863 652 294 972 560 241 459 2;
  • 16) 0.682 581 338 412 522 049 863 652 294 972 560 241 459 2 × 2 = 1 + 0.365 162 676 825 044 099 727 304 589 945 120 482 918 4;
  • 17) 0.365 162 676 825 044 099 727 304 589 945 120 482 918 4 × 2 = 0 + 0.730 325 353 650 088 199 454 609 179 890 240 965 836 8;
  • 18) 0.730 325 353 650 088 199 454 609 179 890 240 965 836 8 × 2 = 1 + 0.460 650 707 300 176 398 909 218 359 780 481 931 673 6;
  • 19) 0.460 650 707 300 176 398 909 218 359 780 481 931 673 6 × 2 = 0 + 0.921 301 414 600 352 797 818 436 719 560 963 863 347 2;
  • 20) 0.921 301 414 600 352 797 818 436 719 560 963 863 347 2 × 2 = 1 + 0.842 602 829 200 705 595 636 873 439 121 927 726 694 4;
  • 21) 0.842 602 829 200 705 595 636 873 439 121 927 726 694 4 × 2 = 1 + 0.685 205 658 401 411 191 273 746 878 243 855 453 388 8;
  • 22) 0.685 205 658 401 411 191 273 746 878 243 855 453 388 8 × 2 = 1 + 0.370 411 316 802 822 382 547 493 756 487 710 906 777 6;
  • 23) 0.370 411 316 802 822 382 547 493 756 487 710 906 777 6 × 2 = 0 + 0.740 822 633 605 644 765 094 987 512 975 421 813 555 2;
  • 24) 0.740 822 633 605 644 765 094 987 512 975 421 813 555 2 × 2 = 1 + 0.481 645 267 211 289 530 189 975 025 950 843 627 110 4;
  • 25) 0.481 645 267 211 289 530 189 975 025 950 843 627 110 4 × 2 = 0 + 0.963 290 534 422 579 060 379 950 051 901 687 254 220 8;
  • 26) 0.963 290 534 422 579 060 379 950 051 901 687 254 220 8 × 2 = 1 + 0.926 581 068 845 158 120 759 900 103 803 374 508 441 6;
  • 27) 0.926 581 068 845 158 120 759 900 103 803 374 508 441 6 × 2 = 1 + 0.853 162 137 690 316 241 519 800 207 606 749 016 883 2;
  • 28) 0.853 162 137 690 316 241 519 800 207 606 749 016 883 2 × 2 = 1 + 0.706 324 275 380 632 483 039 600 415 213 498 033 766 4;
  • 29) 0.706 324 275 380 632 483 039 600 415 213 498 033 766 4 × 2 = 1 + 0.412 648 550 761 264 966 079 200 830 426 996 067 532 8;
  • 30) 0.412 648 550 761 264 966 079 200 830 426 996 067 532 8 × 2 = 0 + 0.825 297 101 522 529 932 158 401 660 853 992 135 065 6;
  • 31) 0.825 297 101 522 529 932 158 401 660 853 992 135 065 6 × 2 = 1 + 0.650 594 203 045 059 864 316 803 321 707 984 270 131 2;
  • 32) 0.650 594 203 045 059 864 316 803 321 707 984 270 131 2 × 2 = 1 + 0.301 188 406 090 119 728 633 606 643 415 968 540 262 4;
  • 33) 0.301 188 406 090 119 728 633 606 643 415 968 540 262 4 × 2 = 0 + 0.602 376 812 180 239 457 267 213 286 831 937 080 524 8;
  • 34) 0.602 376 812 180 239 457 267 213 286 831 937 080 524 8 × 2 = 1 + 0.204 753 624 360 478 914 534 426 573 663 874 161 049 6;
  • 35) 0.204 753 624 360 478 914 534 426 573 663 874 161 049 6 × 2 = 0 + 0.409 507 248 720 957 829 068 853 147 327 748 322 099 2;
  • 36) 0.409 507 248 720 957 829 068 853 147 327 748 322 099 2 × 2 = 0 + 0.819 014 497 441 915 658 137 706 294 655 496 644 198 4;
  • 37) 0.819 014 497 441 915 658 137 706 294 655 496 644 198 4 × 2 = 1 + 0.638 028 994 883 831 316 275 412 589 310 993 288 396 8;
  • 38) 0.638 028 994 883 831 316 275 412 589 310 993 288 396 8 × 2 = 1 + 0.276 057 989 767 662 632 550 825 178 621 986 576 793 6;
  • 39) 0.276 057 989 767 662 632 550 825 178 621 986 576 793 6 × 2 = 0 + 0.552 115 979 535 325 265 101 650 357 243 973 153 587 2;
  • 40) 0.552 115 979 535 325 265 101 650 357 243 973 153 587 2 × 2 = 1 + 0.104 231 959 070 650 530 203 300 714 487 946 307 174 4;
  • 41) 0.104 231 959 070 650 530 203 300 714 487 946 307 174 4 × 2 = 0 + 0.208 463 918 141 301 060 406 601 428 975 892 614 348 8;
  • 42) 0.208 463 918 141 301 060 406 601 428 975 892 614 348 8 × 2 = 0 + 0.416 927 836 282 602 120 813 202 857 951 785 228 697 6;
  • 43) 0.416 927 836 282 602 120 813 202 857 951 785 228 697 6 × 2 = 0 + 0.833 855 672 565 204 241 626 405 715 903 570 457 395 2;
  • 44) 0.833 855 672 565 204 241 626 405 715 903 570 457 395 2 × 2 = 1 + 0.667 711 345 130 408 483 252 811 431 807 140 914 790 4;
  • 45) 0.667 711 345 130 408 483 252 811 431 807 140 914 790 4 × 2 = 1 + 0.335 422 690 260 816 966 505 622 863 614 281 829 580 8;
  • 46) 0.335 422 690 260 816 966 505 622 863 614 281 829 580 8 × 2 = 0 + 0.670 845 380 521 633 933 011 245 727 228 563 659 161 6;
  • 47) 0.670 845 380 521 633 933 011 245 727 228 563 659 161 6 × 2 = 1 + 0.341 690 761 043 267 866 022 491 454 457 127 318 323 2;
  • 48) 0.341 690 761 043 267 866 022 491 454 457 127 318 323 2 × 2 = 0 + 0.683 381 522 086 535 732 044 982 908 914 254 636 646 4;
  • 49) 0.683 381 522 086 535 732 044 982 908 914 254 636 646 4 × 2 = 1 + 0.366 763 044 173 071 464 089 965 817 828 509 273 292 8;
  • 50) 0.366 763 044 173 071 464 089 965 817 828 509 273 292 8 × 2 = 0 + 0.733 526 088 346 142 928 179 931 635 657 018 546 585 6;
  • 51) 0.733 526 088 346 142 928 179 931 635 657 018 546 585 6 × 2 = 1 + 0.467 052 176 692 285 856 359 863 271 314 037 093 171 2;
  • 52) 0.467 052 176 692 285 856 359 863 271 314 037 093 171 2 × 2 = 0 + 0.934 104 353 384 571 712 719 726 542 628 074 186 342 4;
  • 53) 0.934 104 353 384 571 712 719 726 542 628 074 186 342 4 × 2 = 1 + 0.868 208 706 769 143 425 439 453 085 256 148 372 684 8;
  • 54) 0.868 208 706 769 143 425 439 453 085 256 148 372 684 8 × 2 = 1 + 0.736 417 413 538 286 850 878 906 170 512 296 745 369 6;
  • 55) 0.736 417 413 538 286 850 878 906 170 512 296 745 369 6 × 2 = 1 + 0.472 834 827 076 573 701 757 812 341 024 593 490 739 2;
  • 56) 0.472 834 827 076 573 701 757 812 341 024 593 490 739 2 × 2 = 0 + 0.945 669 654 153 147 403 515 624 682 049 186 981 478 4;
  • 57) 0.945 669 654 153 147 403 515 624 682 049 186 981 478 4 × 2 = 1 + 0.891 339 308 306 294 807 031 249 364 098 373 962 956 8;
  • 58) 0.891 339 308 306 294 807 031 249 364 098 373 962 956 8 × 2 = 1 + 0.782 678 616 612 589 614 062 498 728 196 747 925 913 6;
  • 59) 0.782 678 616 612 589 614 062 498 728 196 747 925 913 6 × 2 = 1 + 0.565 357 233 225 179 228 124 997 456 393 495 851 827 2;
  • 60) 0.565 357 233 225 179 228 124 997 456 393 495 851 827 2 × 2 = 1 + 0.130 714 466 450 358 456 249 994 912 786 991 703 654 4;
  • 61) 0.130 714 466 450 358 456 249 994 912 786 991 703 654 4 × 2 = 0 + 0.261 428 932 900 716 912 499 989 825 573 983 407 308 8;
  • 62) 0.261 428 932 900 716 912 499 989 825 573 983 407 308 8 × 2 = 0 + 0.522 857 865 801 433 824 999 979 651 147 966 814 617 6;
  • 63) 0.522 857 865 801 433 824 999 979 651 147 966 814 617 6 × 2 = 1 + 0.045 715 731 602 867 649 999 959 302 295 933 629 235 2;
  • 64) 0.045 715 731 602 867 649 999 959 302 295 933 629 235 2 × 2 = 0 + 0.091 431 463 205 735 299 999 918 604 591 867 258 470 4;
  • 65) 0.091 431 463 205 735 299 999 918 604 591 867 258 470 4 × 2 = 0 + 0.182 862 926 411 470 599 999 837 209 183 734 516 940 8;
  • 66) 0.182 862 926 411 470 599 999 837 209 183 734 516 940 8 × 2 = 0 + 0.365 725 852 822 941 199 999 674 418 367 469 033 881 6;
  • 67) 0.365 725 852 822 941 199 999 674 418 367 469 033 881 6 × 2 = 0 + 0.731 451 705 645 882 399 999 348 836 734 938 067 763 2;
  • 68) 0.731 451 705 645 882 399 999 348 836 734 938 067 763 2 × 2 = 1 + 0.462 903 411 291 764 799 998 697 673 469 876 135 526 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:


0.000 020 830 729 321 671 205 134 999 154 509 660 651 9(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:

0.000 020 830 729 321 671 205 134 999 154 509 660 651 9(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:


0.000 020 830 729 321 671 205 134 999 154 509 660 651 9(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 0.000 020 830 729 321 671 205 134 999 154 509 660 651 9 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