0.000 020 830 729 321 671 205 134 999 154 509 660 588 Converted to 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard

Convert decimal 0.000 020 830 729 321 671 205 134 999 154 509 660 588(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
0.000 020 830 729 321 671 205 134 999 154 509 660 588(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: 0.000 020 830 729 321 671 205 134 999 154 509 660 588.

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) 0.000 020 830 729 321 671 205 134 999 154 509 660 588 × 2 = 0 + 0.000 041 661 458 643 342 410 269 998 309 019 321 176;
  • 2) 0.000 041 661 458 643 342 410 269 998 309 019 321 176 × 2 = 0 + 0.000 083 322 917 286 684 820 539 996 618 038 642 352;
  • 3) 0.000 083 322 917 286 684 820 539 996 618 038 642 352 × 2 = 0 + 0.000 166 645 834 573 369 641 079 993 236 077 284 704;
  • 4) 0.000 166 645 834 573 369 641 079 993 236 077 284 704 × 2 = 0 + 0.000 333 291 669 146 739 282 159 986 472 154 569 408;
  • 5) 0.000 333 291 669 146 739 282 159 986 472 154 569 408 × 2 = 0 + 0.000 666 583 338 293 478 564 319 972 944 309 138 816;
  • 6) 0.000 666 583 338 293 478 564 319 972 944 309 138 816 × 2 = 0 + 0.001 333 166 676 586 957 128 639 945 888 618 277 632;
  • 7) 0.001 333 166 676 586 957 128 639 945 888 618 277 632 × 2 = 0 + 0.002 666 333 353 173 914 257 279 891 777 236 555 264;
  • 8) 0.002 666 333 353 173 914 257 279 891 777 236 555 264 × 2 = 0 + 0.005 332 666 706 347 828 514 559 783 554 473 110 528;
  • 9) 0.005 332 666 706 347 828 514 559 783 554 473 110 528 × 2 = 0 + 0.010 665 333 412 695 657 029 119 567 108 946 221 056;
  • 10) 0.010 665 333 412 695 657 029 119 567 108 946 221 056 × 2 = 0 + 0.021 330 666 825 391 314 058 239 134 217 892 442 112;
  • 11) 0.021 330 666 825 391 314 058 239 134 217 892 442 112 × 2 = 0 + 0.042 661 333 650 782 628 116 478 268 435 784 884 224;
  • 12) 0.042 661 333 650 782 628 116 478 268 435 784 884 224 × 2 = 0 + 0.085 322 667 301 565 256 232 956 536 871 569 768 448;
  • 13) 0.085 322 667 301 565 256 232 956 536 871 569 768 448 × 2 = 0 + 0.170 645 334 603 130 512 465 913 073 743 139 536 896;
  • 14) 0.170 645 334 603 130 512 465 913 073 743 139 536 896 × 2 = 0 + 0.341 290 669 206 261 024 931 826 147 486 279 073 792;
  • 15) 0.341 290 669 206 261 024 931 826 147 486 279 073 792 × 2 = 0 + 0.682 581 338 412 522 049 863 652 294 972 558 147 584;
  • 16) 0.682 581 338 412 522 049 863 652 294 972 558 147 584 × 2 = 1 + 0.365 162 676 825 044 099 727 304 589 945 116 295 168;
  • 17) 0.365 162 676 825 044 099 727 304 589 945 116 295 168 × 2 = 0 + 0.730 325 353 650 088 199 454 609 179 890 232 590 336;
  • 18) 0.730 325 353 650 088 199 454 609 179 890 232 590 336 × 2 = 1 + 0.460 650 707 300 176 398 909 218 359 780 465 180 672;
  • 19) 0.460 650 707 300 176 398 909 218 359 780 465 180 672 × 2 = 0 + 0.921 301 414 600 352 797 818 436 719 560 930 361 344;
  • 20) 0.921 301 414 600 352 797 818 436 719 560 930 361 344 × 2 = 1 + 0.842 602 829 200 705 595 636 873 439 121 860 722 688;
  • 21) 0.842 602 829 200 705 595 636 873 439 121 860 722 688 × 2 = 1 + 0.685 205 658 401 411 191 273 746 878 243 721 445 376;
  • 22) 0.685 205 658 401 411 191 273 746 878 243 721 445 376 × 2 = 1 + 0.370 411 316 802 822 382 547 493 756 487 442 890 752;
  • 23) 0.370 411 316 802 822 382 547 493 756 487 442 890 752 × 2 = 0 + 0.740 822 633 605 644 765 094 987 512 974 885 781 504;
  • 24) 0.740 822 633 605 644 765 094 987 512 974 885 781 504 × 2 = 1 + 0.481 645 267 211 289 530 189 975 025 949 771 563 008;
  • 25) 0.481 645 267 211 289 530 189 975 025 949 771 563 008 × 2 = 0 + 0.963 290 534 422 579 060 379 950 051 899 543 126 016;
  • 26) 0.963 290 534 422 579 060 379 950 051 899 543 126 016 × 2 = 1 + 0.926 581 068 845 158 120 759 900 103 799 086 252 032;
  • 27) 0.926 581 068 845 158 120 759 900 103 799 086 252 032 × 2 = 1 + 0.853 162 137 690 316 241 519 800 207 598 172 504 064;
  • 28) 0.853 162 137 690 316 241 519 800 207 598 172 504 064 × 2 = 1 + 0.706 324 275 380 632 483 039 600 415 196 345 008 128;
  • 29) 0.706 324 275 380 632 483 039 600 415 196 345 008 128 × 2 = 1 + 0.412 648 550 761 264 966 079 200 830 392 690 016 256;
  • 30) 0.412 648 550 761 264 966 079 200 830 392 690 016 256 × 2 = 0 + 0.825 297 101 522 529 932 158 401 660 785 380 032 512;
  • 31) 0.825 297 101 522 529 932 158 401 660 785 380 032 512 × 2 = 1 + 0.650 594 203 045 059 864 316 803 321 570 760 065 024;
  • 32) 0.650 594 203 045 059 864 316 803 321 570 760 065 024 × 2 = 1 + 0.301 188 406 090 119 728 633 606 643 141 520 130 048;
  • 33) 0.301 188 406 090 119 728 633 606 643 141 520 130 048 × 2 = 0 + 0.602 376 812 180 239 457 267 213 286 283 040 260 096;
  • 34) 0.602 376 812 180 239 457 267 213 286 283 040 260 096 × 2 = 1 + 0.204 753 624 360 478 914 534 426 572 566 080 520 192;
  • 35) 0.204 753 624 360 478 914 534 426 572 566 080 520 192 × 2 = 0 + 0.409 507 248 720 957 829 068 853 145 132 161 040 384;
  • 36) 0.409 507 248 720 957 829 068 853 145 132 161 040 384 × 2 = 0 + 0.819 014 497 441 915 658 137 706 290 264 322 080 768;
  • 37) 0.819 014 497 441 915 658 137 706 290 264 322 080 768 × 2 = 1 + 0.638 028 994 883 831 316 275 412 580 528 644 161 536;
  • 38) 0.638 028 994 883 831 316 275 412 580 528 644 161 536 × 2 = 1 + 0.276 057 989 767 662 632 550 825 161 057 288 323 072;
  • 39) 0.276 057 989 767 662 632 550 825 161 057 288 323 072 × 2 = 0 + 0.552 115 979 535 325 265 101 650 322 114 576 646 144;
  • 40) 0.552 115 979 535 325 265 101 650 322 114 576 646 144 × 2 = 1 + 0.104 231 959 070 650 530 203 300 644 229 153 292 288;
  • 41) 0.104 231 959 070 650 530 203 300 644 229 153 292 288 × 2 = 0 + 0.208 463 918 141 301 060 406 601 288 458 306 584 576;
  • 42) 0.208 463 918 141 301 060 406 601 288 458 306 584 576 × 2 = 0 + 0.416 927 836 282 602 120 813 202 576 916 613 169 152;
  • 43) 0.416 927 836 282 602 120 813 202 576 916 613 169 152 × 2 = 0 + 0.833 855 672 565 204 241 626 405 153 833 226 338 304;
  • 44) 0.833 855 672 565 204 241 626 405 153 833 226 338 304 × 2 = 1 + 0.667 711 345 130 408 483 252 810 307 666 452 676 608;
  • 45) 0.667 711 345 130 408 483 252 810 307 666 452 676 608 × 2 = 1 + 0.335 422 690 260 816 966 505 620 615 332 905 353 216;
  • 46) 0.335 422 690 260 816 966 505 620 615 332 905 353 216 × 2 = 0 + 0.670 845 380 521 633 933 011 241 230 665 810 706 432;
  • 47) 0.670 845 380 521 633 933 011 241 230 665 810 706 432 × 2 = 1 + 0.341 690 761 043 267 866 022 482 461 331 621 412 864;
  • 48) 0.341 690 761 043 267 866 022 482 461 331 621 412 864 × 2 = 0 + 0.683 381 522 086 535 732 044 964 922 663 242 825 728;
  • 49) 0.683 381 522 086 535 732 044 964 922 663 242 825 728 × 2 = 1 + 0.366 763 044 173 071 464 089 929 845 326 485 651 456;
  • 50) 0.366 763 044 173 071 464 089 929 845 326 485 651 456 × 2 = 0 + 0.733 526 088 346 142 928 179 859 690 652 971 302 912;
  • 51) 0.733 526 088 346 142 928 179 859 690 652 971 302 912 × 2 = 1 + 0.467 052 176 692 285 856 359 719 381 305 942 605 824;
  • 52) 0.467 052 176 692 285 856 359 719 381 305 942 605 824 × 2 = 0 + 0.934 104 353 384 571 712 719 438 762 611 885 211 648;
  • 53) 0.934 104 353 384 571 712 719 438 762 611 885 211 648 × 2 = 1 + 0.868 208 706 769 143 425 438 877 525 223 770 423 296;
  • 54) 0.868 208 706 769 143 425 438 877 525 223 770 423 296 × 2 = 1 + 0.736 417 413 538 286 850 877 755 050 447 540 846 592;
  • 55) 0.736 417 413 538 286 850 877 755 050 447 540 846 592 × 2 = 1 + 0.472 834 827 076 573 701 755 510 100 895 081 693 184;
  • 56) 0.472 834 827 076 573 701 755 510 100 895 081 693 184 × 2 = 0 + 0.945 669 654 153 147 403 511 020 201 790 163 386 368;
  • 57) 0.945 669 654 153 147 403 511 020 201 790 163 386 368 × 2 = 1 + 0.891 339 308 306 294 807 022 040 403 580 326 772 736;
  • 58) 0.891 339 308 306 294 807 022 040 403 580 326 772 736 × 2 = 1 + 0.782 678 616 612 589 614 044 080 807 160 653 545 472;
  • 59) 0.782 678 616 612 589 614 044 080 807 160 653 545 472 × 2 = 1 + 0.565 357 233 225 179 228 088 161 614 321 307 090 944;
  • 60) 0.565 357 233 225 179 228 088 161 614 321 307 090 944 × 2 = 1 + 0.130 714 466 450 358 456 176 323 228 642 614 181 888;
  • 61) 0.130 714 466 450 358 456 176 323 228 642 614 181 888 × 2 = 0 + 0.261 428 932 900 716 912 352 646 457 285 228 363 776;
  • 62) 0.261 428 932 900 716 912 352 646 457 285 228 363 776 × 2 = 0 + 0.522 857 865 801 433 824 705 292 914 570 456 727 552;
  • 63) 0.522 857 865 801 433 824 705 292 914 570 456 727 552 × 2 = 1 + 0.045 715 731 602 867 649 410 585 829 140 913 455 104;
  • 64) 0.045 715 731 602 867 649 410 585 829 140 913 455 104 × 2 = 0 + 0.091 431 463 205 735 298 821 171 658 281 826 910 208;
  • 65) 0.091 431 463 205 735 298 821 171 658 281 826 910 208 × 2 = 0 + 0.182 862 926 411 470 597 642 343 316 563 653 820 416;
  • 66) 0.182 862 926 411 470 597 642 343 316 563 653 820 416 × 2 = 0 + 0.365 725 852 822 941 195 284 686 633 127 307 640 832;
  • 67) 0.365 725 852 822 941 195 284 686 633 127 307 640 832 × 2 = 0 + 0.731 451 705 645 882 390 569 373 266 254 615 281 664;
  • 68) 0.731 451 705 645 882 390 569 373 266 254 615 281 664 × 2 = 1 + 0.462 903 411 291 764 781 138 746 532 509 230 563 328;

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:


0.000 020 830 729 321 671 205 134 999 154 509 660 588(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:

0.000 020 830 729 321 671 205 134 999 154 509 660 588(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:


0.000 020 830 729 321 671 205 134 999 154 509 660 588(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 0.000 020 830 729 321 671 205 134 999 154 509 660 588 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